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DemProj Manual - Johns Hopkins Bloomberg School of Public Health

1. DemProj Version 4 A Computer Program for Making Population Projections Spectrum System of Policy Models By John Stover Futures Group and Sharon Kirmeyer Research Triangle Institute POLICY Project Spectrum A Computer Program for Making Population Projections Spectrum System of Policy Models By John Stover Futures Group and Sharon Kirmeyer Research Triangle Institute POLICY II is a five year project funded by the U S Agency for International Development under Contract No HRN C 00 00 00006 00 beginning July 7 2000 It is implemented by the Futures Group in collaboration with Research Triangle Institute RTI and the Centre for Development and Population Activities CEDPA April 2005 Table of Contents ss INTRODUCTION a sscsiacatcesiacsiccticeed detdaeetceticead daidanascetdaeudisiscnascetiecatiessccesceteustinwseeascetsees 1 A Description of the Spectrum System cccccccccssssssssssscecccccceesesssssseeeeees 1 Me Ee a SOINE Siiss dere tos cas ded ecuesele S E E EE E E 2 Software Descr O a A AAN Eaa 2 B Uses of Spectrum Policy Models ccccccccssssssssssseecccccceceesssssesecceceeeeees 2 C Organization of the Model MANnuaIs ssssscccccccccssssssssssseccccceeeeeeesesees 4 D Information about the POLICY Project esessssesseeeeeossssseseeeeccsssssesseeeeeee 4 E What IS DemMPrOj iii se vicetiecattavacavacectadeidavazavatavianaiQanh
2. Once you have successfully entered all the necessary data click on the Sex ratio at birth tab to move to this editor Sex Ratio at Birth This sex ratio at birth the number of male births per 100 female births is set by default to 105 For most countries it will be about 103 to 105 You may enter a new number in the edit cell or accept the default value a message warning box will appear if an invalid number such as 300 is entered Once you have specified the birth ratio click on the Life expectancy tab to move to this editor Life Expectancy The life expectancy editor see sample screen below is used to enter the life expectancy at birth for both males and females in the base year and to enter assumed values for future years The first few years will be shown on the screen 1 Click somewhere inside the editor to make the scroll bar appear 2 Scroll to the right or left to see all the years 3 Enter life expectancy for every year of your projection Spectrum laj x File Edit Display Options Window Help Demographic data SAMPLE _ OP x Edit First year population Total fertility rate ASFR if Sex ratio at birth Life expectancy Model life table Intemational migration Life expectancy 1992 1993 1994 1995 1996 1997 1998 1999 2000 Male 641 65 0 658 667 67 6 684 693 70 1 71 0 66 2 67 0 677 684 691 69 8 706 713 72 0 Ok Cancel Duplicate _
3. 50 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group 1975 BFS TFR 6 TFR 5 TFR 4 TFR 3 Figure A 2 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs Bangladesh BFS 1989 reference fertility schedule BFS 1989 births per thousand women 50 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group 1989 BFS TFR 6 TFR 5 TFR 4 TFR Table A 2 Bangladesh ASFRs from Various Surveys and Projected Rates ASER by Source Age Group 1975 BFS 1989 BFS 1991 CPS DAS 15 19 109 182 179 140 20 24 289 260 230 196 25 29 291 225 188 148 30 34 250 169 129 105 35 39 185 114 78 56 40 44 107 56 36 19 45 49 35 18 13 14 Empirical TFR 6 33 DMZ 4 27 3 39 Reference Fertility 1975 Bangladesh Fertility Survey 15 19 108 105 101 95 20 24 287 279 269 251 25 29 283 254 216 164 30 34 234 181 123 63 35 39 166 111 61 22 40 44 93 54 24 6 45 49 30 16 6 1 Projected TFR 6 5 4 3 Coale Trussell model Reference Fertility 1989 Bangladesh Fertility Survey 15 19 161 181 174 161 20 24 266 259 248 230 25 29 248 222 186 136 30 34 213 163 108 51 35 39 163 108 57 17 40 44 91 52 22 4 45 49 32 16 6 1 Projected TFR 6 5 4 3 Coale Trussell model Spectrum FROM THE AMERICAN PEOPLE Po uicY For more information please contact Director POLICY Project Futures
4. Select that tab and you will see the Regional assumptions editor EJ There are two methods for entering regional assumptions The editor will first appear with the button Enter percentage directly chosen In this editor you may enter the percentage of the entire population that is urban for each year in the projection Note The term regional may apply more broadly than to the rural urban distinction It may refer to a geographic distinction highlands lowlands a cultural distinction indigenous foreign or a political distinction north south etc To use the other method for making regional projections click the Use growth rate difference button That editor requires two pieces of information the base year growth rates of the urban and rural populations 4 Leaving the Demographic Data Editors Once you have entered all the necessary information 1 Leave the demography editors by clicking on the Ok button in any of the editors When you click the Ok button the program will record your changes and return to the Demographic data dialogue box 2 Click on Close to keep your work and you will return to the main program If you decide that you do not want to keep the changes you have just made click the Cancel button in any editor This will exit the demography editors and restore all inputs to their values before you entered the demography editor Any changes you made
5. where urban urban population at time t rural rural population total total population URGD urban rural growth rate difference This equation is actually a logistic function The urbanization rate will slow after the percent of the population which is urban passes 50 percent The URGD is a combination of the difference in the urban and rural growth rates actually experienced in the most recent time period and the hypothetical difference calculated with the equation URGD 0 044 0 028 initial fraction urban The rural population is calculated as the difference between the total population and the urban population ee This method is described fully in Methods for Projections of Urban and Rural Population Manual VIII United Nations 1974 The age distributions of the urban and rural populations are also calculated as logistic functions This procedure makes use of the logit function The logit of the percent urban is defined to be 0 5 Ln percent urban 1 percent urban In this approach the logit of the percent urban in each age group is assumed as a first approximation to increase as the logit of the total percent urban As an illustration consider the steps in calculating the size of the 10 14 urban age group in 1985 First we calculate the increase in the logit of the percent of the total population that is urban IUL logit urban in 1985 logit urban in 1980 where IUL increase in ur
6. schools doctors nurses urban housing or food requires knowledge of the number of people who will be requiring services Thus population projections serve as the starting point for most projections of future need Population projections are also important for policy dialogue A key aspect of the policy process is recognizing that a problem exists and placing that problem on the policy agenda Since rapid population growth contributes to many of the major development problems population projections are required to illustrate the future magnitude of the problems For example a population projection is required in order to illustrate the future threat to forests from excessive use of fuel wood Population projections are required also in areas of the policy process that involve proposals to solve problems In this case population projections are required to show the magnitude of the services that will be required for the proposed solution and the improvements in population based indicators that will occur For example a discussion of the need for and impact of an expanded program of immunization requires a population projection to show the number of children who will need vaccination in the future and the reduction in morbidity and mortality rates that could be achieved by the proposed program Looking at future population composition and size usually requires producing several projections for two reasons First projections are based
7. Interpolate Source Ready 0 SAMPLE If you want to keep the life expectancy constant at the base year value you can enter the base year value and then use the Duplicate key To copy a value 1 Highlight select the range The first cell in the range should be the value you want to copy Extend the range to the last year using the mouse hold down the left button and drag the range to the right or the keyboard hold down the shift key and use the right arrow key to scroll to the right 2 Then click on the Duplicate key This step will copy the value at the beginning of the range to all the other cells in that range a B You may want to enter a life expectancy value for the first year and the last year and interpolate between these values to fill in the intervening years To do this 1 Enter the life expectancy values in the first and last years 2 Highlight select the entire range from the first to the last year 3 Press the Interpolate key Values will be interpolated and entered for each of the years between the first and last When you have entered the information on the life expectancy click the Model life table tab to move to this editor Model Life Table Once you click the Model life table tab you should see a dialogue box like the one shown below Spectrum _ 16 x Fie Edit Display Options Window Help Demographic data SAMPLE First year
8. Source button 1 Click on the Source button to open a small word processor window 2 Enter the source of the data and make any special comments about the assumptions 3 Click on Close to return to the editor This feature allows you to keep a record of the data sources and assumptions as you make the projections This source information will be maintained with the data file and printed whenever you print the projection summary It is strongly recommended that you use this feature to avoid later confusion When you have finished entering all the necessary data for the component into the editor 1 Click the Ok button to return to the Sector selection dialogue box 2 Click the Close button to complete the editing process or 3 Click on another sector to edit the data for that sector The Cancel button allows you to exit the editor without making any changes to the data for the sector First Year Population The population by age and sex in the base year is entered in this editor The scale is shown at the top of the editor In our example the scale we chose was Thousands Thus a figure such as 43 230 would be entered as 43 23 l Enter the size of the population by age and sex in the appropriate cells of the editor The total number of males and females will be automatically calculated and displayed in the last row of each column 2 If your projection includes an ur
9. including the Demographic and Health Surveys DHS the Centers for Disease Control and Prevention CDC Fertility Surveys the Contraceptive Prevalence Surveys CPS and the World Fertility Surveys WFS Information from these and other national surveys is collected and reported in a variety of sources including summary reports from the DHS the Population Reference Bureau s World Population Data Sheet and the World Bank s World Development Indicators Future Assumptions An assumption about the future TFR is required for most population projections There are several options for setting the TFR projection 1 National projections Many countries have official population projections that include assumptions about the future course of their TFRs often with several variants If population projections are being made for planning purposes it is often recommended that the official assumptions and projections be used 2 National goals Many countries have national population goals that often include the TFR It may be useful to use these goals as a starting point for projections One projection may assume that the TFR goal is achieved while others may examine the effects of a delay in achieving the goal Sometimes goals are expressed in terms of crude birth rates population growth rates or contraceptive prevalence rates instead of TFR In these cases different TFR assumptions may be used to discover a TFR projection that is
10. which will survive one age group into the next five year group The majority of countries to which DemProj has been applied have had no complete empirical life talbbles and life tables are what yields survival ratios or sx Even if there were such tables generally little is known about how the pattern of mortality would evolve given projected changes in mortality BJ levels In addition entering data for a life table function for all 18 age groups is burdensome So for both parsimony and consistency with studied patterns DemProj employs model life tables Regional Model Life Tables Two sets of model life tables are employed by DemPro the Coale Demeny Coale Demeny and Vaughan 1983 model tables and the United Nations tables for developing countries United Nations 1982 These two sets differ in 1 the algorithm they use to generate the mortality schedules and 2 the empirical data sets from which they were drawn Coale Demeny life tables from Europe and other industrialized regions from the first half of the 20th century the United Nations life tables from developing countries from the second half of the 20th century But the two model sets are similar in one important respect they contain regional families that are distinguished by underlying causes of death Referring to the regions from Europe whose life tables provided distinct patterns the Coale Demeny families are known as North East South and the non
11. Africa TFR 6 Africa TFR 7 Figure 14 Fertility Distribution by TFR UN Arab Pattern percent distribution 0 sal 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group Arab TFR 2 Arab TFR 3 Arab TFR 4 x Arab TFR 5 Arab TFR 6 Arab TFR 7 Figure 15 Fertility Distribution by TFR UN Asia Pattern percent distribution 35 30 25 20 15 10 5y 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group Asia TFR 2 Asia TFR 3 Asia TFR 4 gt Asia TFR 5 Asia TFR 6 Asia TFR 7 Total births are found by summing births to women in all the reproductive ages births births Births by sex are calculated from total births and the proportion of births of that sex The proportion of male births is equal to the sex ratio at birth divided by the ratio plus 100 The proportion of female births is one minus the proportion of male births birthsst births PBSs PBSmale SexRatioAtBirth SexRatioAtBirth 100 PBStemaie 1 PBSmale G Urban and Rural Projections The methodology of projecting urban and rural populations follows the United Nations method of growth rate difference In this method the size of the urban population is projected as follows urban urban totali URGD e ruralt 1 totali 1
12. Group Suite 200 One Thomas Circle NW Washington DC 20005 Telephone 202 775 9680 Fax 202 775 9694 E mail policyinfo futuresgroup com
13. System consolidates previous models into an integrated package containing the following components Demography DemProj A program to make population projections based on 1 the current population and 2 fertility mortality and migration rates for a country or region Family Planning FamPlan A program to project family planning requirements in order to achieve national goals for meeting couples fertility intentions Benefit Cost A program for comparing the costs of implementing family planning programs to the benefits generated by those programs AIDS AIDS Impact Model AIM A program to project the consequences of the AIDS epidemic including the number of people infected with HIV AIDS deaths the number of people needing treatment and the number of orphans Socioeconomic Impacts of High Fertility and Population Growth RAPID A program to project the social and economic consequences of high fertility and rapid population growth for sectors such as labor force education health urbanization and agriculture Adolescent reproductive health NewGen A program to estimate the consequences of adolescent reproductive health behavior including sexual debut marriage pregnancy abortion and HIV STI infection Prevention of mother to child transmission PMTCT A program to examine the costs and benefits of interventions to prevent the transmission of HIV from mother to child
14. You can change the configuration of the display by clicking the Configure button You can also change the type of display by putting the mouse pointer anywhere inside the chart and clicking with the right mouse button To close the display click on the Close button You do not have to close the display immediately You can choose to display another indicator and it will appear on top of the first display The first display will be covered but it will still be there You can return to any previous display that you have not closed by choosing Window from the menu bar and selecting the name of the display from the pull down menu From the Window selection you can also choose to tile or cascade all the existing display windows Co 1 Graphs and Bar Charts Spectrum will display a variety of graphs and bar charts including e Line charts Two and three dimensional bar charts column charts e Two and three dimensional horizontal bar charts Two and three dimensional overlap bar charts bars for multiple projections are shown on top of each other Three dimensional perspective bar charts To print the active chart select File from the menu bar and Print from the pull down menu 2 Tables Spectrum will also display data in the form of tables In tables each projection that is in use will be displayed in a separate column You can scroll through the table to see alll the years using the
15. a value 1 Highlight select the range The first cell in the range should be the value you want to copy Extend the range to the last year using the mouse hold down the left button and drag the range to the right or the keyboard hold down the shift key and use the right arrow key to scroll to the right 4S 2 Then click on the Duplicate key This step will copy the value at the beginning of the range to all the other cells in that range You may want to enter a TFR value for the first year and the last year and interpolate between these values to fill in the intervening years interpolation may be done for any interval of time To do this 1 Enter the TFR values in the first and last years 2 Highlight select the entire range from the first to the last year 3 Press the Interpolate key Values will be interpolated and entered for each of the years between the first and last When you have entered the information on the TFR click the ASFR tab to move to the next editor ASFR This editor is used to set the distribution of fertility by age It will look similar to the screen shown below Spectrum lej x File Edit Display Options window Help Demographic data SAMPLE Life expectancy Model life table International migration First year population Total fertility rate Srna Use model table C Coale Trussel C Enter from keyboard C UN sub Saharan Africa CBR 28
16. be carefully considered and based on reasonable selection guidelines Enter data Once the base year data are collected and decisions are made about projection assumptions DemProj can be used to enter the data and make a population projection Examine projections Once you make a projection it should be examined carefully This scrutiny includes consideration of the various demographic indicators produced as well as the age and sex distribution of the projection Careful examination of these indicators can act as a check to ensure that the base data and assumptions were understood and were entered correctly into the computer program This careful examination is also required to ensure that the consequences of the assumptions are fully understood Make alternative projections Many applications require alternative population projections Once the base projection has been made the program can be used to generate alternative projections quickly by varying one or more of the projection assumptions Hl Demographic Inputs and Outputs This section covers the DemProj inputs in the order that the model needs them Base year population by age and sex Fertility Mortality International migration Overall these inputs fit into one of the three population Model schedules are often processes fertility mortality and migration A population used to model patterns of projection accommodates these processes by using mortal
17. during the current editing session will be lost 5 Saving the Input Data Once you have entered the projection assumptions it is a good idea to save the data onto your hard disk To do this select File from the menu bar and Save projection from the pull down menu The data will be saved using the file name you specified earlier E Making the Projection Whenever you enter data for a new projection or edit the assumptions DemProj will note that the data have been changed The next time you try to display an indicator it will inform you that the data may have changed and ask if you want to recalculate the projection Normally you should answer Yes to this question DemProj will then make the nn B population projection This may take only a few seconds if you are making only a population projection or could take somewhat longer if you are also making a projection including AIDS family planning or reproductive health Once the projection is made you will not be asked again if you want to project the population unless you edit the assumptions F Examining the Output To see the results of the projection select Display from the menu bar From the pull down menu select Demography You will then see another menu showing the seven categories of indicators available Population Fertility Mortality Vital events Ratios Age groups Summary Choose one of these categor
18. most age groups is calculated as the number of people one year younger one year ago plus the net migration during the year minus the number of deaths POPas t POPa 1st 1 Migra 1 s t 1 deathsa st 1t For the last age group the population also includes those who were in the last age group one year ago and survive to the present year POPs0 5 t POP79 s t 1 MIQr79st 1 Aeaths7ost 1 4 POPso st 1 MIQrso s t 1 deathSso s t 1 t The population under one year of age is calculated as the number of births during the year that survive to the end of the year plus the net migrants POpost birthss Migrost i deathsost 1 t F Births The number of births in a year is calculated from the number of women of reproductive age the TFR and the age distribution of fertility birthSat TFR ASFPat POPa female t where birthsat the number of births to women at age a TFR the total fertility rate at time t ASFPat the proportion of lifetime fertility that takes place at age a Figures 13 14 and 15 show the United Nations model proportions by TFR and by region Figure 13 Fertility Distribution by TFR UN Sub Saharan Africa Pattern percent distribution 0 35 30 25 20 15 10 5 el 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group Africa TFR 2 Africa TFR 3 x Africa TFR 4 Africa TFR 5
19. not total to 100 you will see a warning message when you try to exit this editor The message will say At least one column total lt 99 9 Return to editor or At least one column total gt 100 Return to editor If you get either of these messages you should click on Yes to return to the editor and correct the inputs File Edit Display Options Window Help Demographic data SAMPLE Life expectancy Model life table First year population Total fertility rate ASFR Sex ratio at birth C Coale Trussel 25 32 26 61 26 88 26 14 20 89 20 94 13 18 12 51 11 51 5 62 5 17 1 10 0 90 100 00 A 100 00 100 00 Source Ready 0 SAMPLE Coale Trussell Model If you wish to use the Coale Trussell model then click on the button Coale Trussell The bottom part of the screen will change to display a spreadsheet type editor see sample screen below Enter the age distribution of fertility in the base year The Input TFR will be imported automatically from the Total fertility rate editor a message will warn you If the TFR calculated here does not match the Input TFR Demographic data SAMPLE The Duplicate and Interpolate buttons function in the same manner as for the First year population editor You may see the values as a table or a chart If you want to see a table of the actual values that have been calculated from the UN fertility model tabl
20. population into two numerically equal groups Net reproduction rate NRR The average number of daughters that would be born to a woman or a group of women during her lifetime if she passed through all her childbearing years conforming to the age specific fertility rates and age specific mortality rates of a given year This is similar to the GRR except that it includes the effect of mortality that would cause some women to die before completing their childbearing years Rate of natural increase RNI The rate at which the population is increasing or decreasing in a given year due to the surplus or deficit of births over deaths expressed as a percentage of the base population Sex ratio The number of males per 100 females in a population Total fertility rate TFR The average number of children that would be born alive to a woman or a group of women during her lifetime if she were to pass through all her childbearing years conforming to the age specific fertility rates of a given year Under five mortality rate U5MR The number of deaths to children under the age of five per 1 000 live births EJ IV Program Tutorial This tutorial covers the key steps in installing and running Spectrum and DemProj If assumes that you have a computer running Windows 98 or later version and that you are familiar with the basic operation of Windows programs and terminology A Before You Get Started You will need to c
21. same for different populations the intensity of birth control is also proportional to a standard age schedule and the age shape of the proportion currently in unions is similar to the age specific proportion of ever married individuals in a female population nn Formally according to the model any set of the age specific fertility rates fx is graduated as follows f G eMenxe e myx Elements of this formula are the following Functions nx and vx are model standard schedules constant over populations nx is the standard schedule of natural fertility vx is a standard pattern of birth control impact on fertility In addition m is the model parameter of birth control It might considered an index of birth control measuring the degree of fertility reduction below the natural level The shape of vx however leads to the conclusion that the birth control factor represents stopping behavior a policy to terminate childbearing after a certain parity rather than spacing behavior a policy to postpone childbearing M is the level parameter Since natural fertility may vary significantly from population to population the parameter M might be explained as a natural fertility level influenced in a population of women in union primarily by breastfeeding However it also represents the intensity of fertility regulation applied within young ages postponing basically where vx is set to 0 And thus values of M e
22. the bottom of the screen and enter the name of the file containing the life table information a International Migration International migration is specified through three input screens When you select the International migration tab you will see the editor shown below File Edit Display Options Window Help Demographic data SAMPLE Todien ae Life expectancy Model life table Total Net Migrants per Year Thousands Net migration Male age distribution Female age distribution Ok Cancel Duplicate _ Interpolate Source Ready 0 SAMPLE In this editor you specify the number of net male and female migrants If the direction of the net migration is out of the country then the figures should be negative if the direction of the net migration is into the country then the figures should be positive Enter figures for male and female migration for all years If you leave the figures set to zero there will be no effect of international migration in the projection Once you have specified the net number of migrants you need to specify the age distribution of these migrants Click on the Male age distribution button to enter the age distribution for male migrants and the Female age distribution button to enter the distribution for female migrants Regional Assumptions If you are including an urban and rural projection there will be a tab for Regional assumptions
23. to be used for this purpose Estimates of life expectancy are usually derived instead from large scale surveys or censuses The best source of information on life expectancy will Usually be national reports prepared by analyzing these surveys If national estimates are not available life expectancy estimates may be obtained from a variety of other sources including the United Nation s World Population Prospects or the Demographic Yearbook the U S Census Bureau s World Population Profile the World Population Data Sheet of the Population Reference Bureau or the World Bank s World Development Indicators Future Assumptions An assumption about future levels of life expectancy at birth is required for all population projections There are several options for setting the life expectancy assumption 1 National projections Many countries have official population projections that include assumptions about the future course of life expectancy often with several variants If population projections are being made for planning purposes it is offen recommended that the official assumptions and projections be used a 2 National goals Many countries have national population goals that include life expectancy It is often useful to use these goals as a starting point for projections In one projection it may be assumed that the life expectancy goal has been achieved while in others model users may examine the effects of a delay in achieving
24. you can use Windows Explorer to 2 To remove the Spectrum program from your hard disk run the unwise exe program located in the Spectrum directory 40 locate the directory c spectrum and double click on the file named spectrum exe 2 Specifying the Projection Parameters in Projection Manager To create a new projection a Select File from the menu bar b From the pull down menu that appears choose New projection Next the Projection manager dialogue box will appear and will look like the following screen Projection manager x First Year Final Year Projection file name Standard demographic projection lt 50 years Easyproj C Demographic projection gt 50 years Active modules I Adolescents YARH l Family planning FamPlan AIDS AIM RAPID I FP Training ProTrain Cancel l BenefitCost a MCT The following information is required to create a new projection Projection title Enter the title you wish to assign to this projection This title will be printed at the top of all printed output and will be used to identify the projection if more than one projection is loaded at a time Projection file name You must also assign a file name to the projection This is the name that will be used to store all data files associated with this projection This name must obey the usual DOS based rules for file names i e it should not
25. 202 775 9694 E mail policyinfo futuresgroup com htto www FuturesGroup com or The POLICY Project U S Agency for International Development Center for Population Health and Nutrition 1300 Pennsylvania Ave Washington DC 20523 U S A Telephone 202 712 5787 or 5839 EJ E What Is DemProj DemProj is designed to produce information useful for policy formulation and dialogue within a framework of easy to use computer programs The demographic model in Spectrum known as DemProj is a computer program for making population projections for countries or regions The program requires information on the number of people by age and sex in the base year as well as current year data and future assumptions about the total fertility rate TFR the age distribution of fertility life expectancy at birth by sex the most appropriate model life table and the magnitude and pattern of international migration all of these inputs are discussed in Chapter Ill This information is used to project the size of the future population by age and sex for as many as 150 years into the future If desired the projection can also estimate the size of the urban and rural populations Linking DemProj with other modules in Spectrum makes it possible to examine the demographic impact of AIDS AIM the family planning service requirements to achieve demographic and health goals FamPlan the costs and benefits of family planning programs and the s
26. 9 CUN Arab CBR 28 1 C UN Asia CBR 27 6 Average CBR 28 2 Selected Comparison Ok Cancel Ready 0 SAMPLE There are three ways to specify the age distribution of fertility You can use the United Nations fertility model tables enter your own distribution or use the Coale Trussell fertility model s B see the glossary or Chapter Ill for more about these distributions United Nations Model Tables The default is to use the United Nations model tables Select an option by clicking on the button next to the name of the table you want to use To the right of each table name you can see the crude birth rate that would be calculated for the base year if you selected that table This column will show CBR 0 0 for all tables if you have not yet entered the base year population or TFR Data for the age distribution of fertility will be calculated from the TFR and the selected model table only when you leave the Demographic data editor Your Own Data If you wish to enter your own data for the age distribution of fertility then click on the button Enter from keyboard The bottom part of the screen will change to display a soreadsheet type editor see screen below Enter your data into the appropriate cells The total for each year will be calculated and displayed in the last row The total for each year should be equal to 100 before you leave this editor If even one column does
27. A Ee 25 1 Life Expectancy at Birth eessssesseessseessecssseessecesseesseeessereseeseecssreesseeesseese 25 REEE EE EE AEEA NAE EE A Bead 25 F t re ASSUMPHONS Sas axusaclntsetcrwal vos vel acsssioosacsad osha sdacountuas vel cuatuniascasoslateatguntuocuetiseateneude 25 2 lite Expectancy CCl ARDS tat nnn nnn a a n a 27 nn 3 AOS SOS CIN IM OMONN Yossi tat iss cecaiusaneearaaveteletu e ietsnceaderenaeae 28 Model Mortality TASS scasictvectssvtaas wane teatiaswiontead deuiauieatcausmiuiaaemualns 28 Regional Model Life TADIES oe ccccsescessssssssessscssssesssssssssssssssscsssssssssssssessssssssesseesens 29 Selecting a Model Life TAbIE wisieRitiiatha cia isutiinaaaisindaes 32 Modifying The Model Life Tables siicucseeitiece actinic atid lanai al dives 33 Dies IMMIQEGMNON EAR a tdacal ivadactl ectdacihe E EEE EE 34 E Current Population Urban and Rul d ccccccsssssssssceccccceeeeeessssseeeeeees 35 Fs Projection OUIPUIS osien reee ren orena ne noaee ne noaee aaen e reee aenor Eos aeeoe ee neauasasancuacetavchase 37 IV PROGRAM TUTORIAD zisccuseaseccecenicucs cazavacesacacecs NKEA EENE EEOAE 39 A Before You Get Started csccccccccccccccssssscsececcccceeeeeesssssceccceceeeeeeeeseees 39 B Installing the Spectrum ProgramM ssssssseeeessessssssooecessssssssoooeeessssssssssoee 40 C Creating a New Projection cccccccccccccccccecccececccecceeeececceeeeeeeececeeeeeeeeees 40 1 Starting the Spectrum Pro
28. Age Groups ai vcrisieiess ch ciaanie adic favtuesenn seen okra anaes vegas 63 4 Demographic Summary MODIS visi stcacetsth vdecusta hace useage ranuereceieaueds 64 i G Saving the PrOlSC OM es oc cssasssavevcnnveepen uses cuseveseeeiw ava visevaviteseeae ees eee 64 H Opening an Existing Projection sscccccccccssssssssssssceccccceeeeeesssssseeeeees 65 I Closing d PrOjO CHOON cisscccicccsscescsssesssdisdscastessassulisdesnccsssesesdsbdesescentecesoessesenessee 65 J Using DemProj Projections with the Excel Version of RAPID 66 K Importing a Demographic Projection Produced with an Earlier Version of DEMPIO os cscecssscsdecscscscnnsconsdndsdnnsdenscdesdenddsnsdensdsnsdsdsdecbdecsdecsdsesdsess 66 L Aggregat ing projections oooeeeeeoesssssssseeecocsssssesseececcsssssssseeecccsssssessee 67 V METHODOLOG Yorcrrsesesresirroseveeririsitis tserte s tit soea Esnes rE EOE EEEE EEEE enaeeeeiads 69 A Calculating the Base Population by Single Age ccccccccssssssseeees 69 B S rvival RONOS sco cidecieecisacitenisacitenisasiteniacitaniuasitenduasibesilassbdmilessbemilaschdwavenatasdes 7 Cz Migration cascsssssassccccccccscsosasiiseniceccasctesasavecsecccectevesasedseadceccasatesasevecasetdeasesesaseds 7 DD x DS CATES ocec waa eles wicca ea eck ae xs wet ah sent ae sh west heen hen ke ee 7 E PODUIONON SIZE sea ee RA ae Seen Ga eee 72 E 1a E 73 G Urban and Rural Proje Cton
29. In DemProj this information is entered as the percentage of lifetime fertility that occurs in the five year age groups 15 19 20 24 25 29 30 34 35 39 40 44 and 45 49 Age at childbearing is relevant for reproductive health The age of the mother may be of particular concern to the well being of the infant with younger ages being associated with risks Of premature delivery or protracted labor and older ages with congenital malformations The mother herself also may be adversely affected by extremes in age of childbearing Women who bear children at younger ages may be physically and socially unprepared and older mothers may face aggravated anemia or hemorrhagic complications Use of Fertility Models in Population Projections As noted earlier in DemProj model schedules are used to generate age patterns in conjunction with levels of fertility mortality and migration Projected fertility is affected by certain age characteristics For example appropriate fertility rates need to be assigned by age group as those groups vary in size which contributes to the size of the population being projected to the next time period In addition some implications of population 16 projections follow from the age of the mothers as they bear children Fertility Surveys Information on the initial age distribution of fertility is Usually available from national fertility surveys It may be reported as age specific fertility rates the num
30. PgUp and PgDn keys or the mouse To print a table select File from the menu bar and Print from the pull down menu 3 Displaying All Age Groups If you wish to see the population size by age and sex choose Display Demography Age groups and then All age groups You can display the information as a table or as a population pyramid see glossary showing either numbers of people Pyramid numbers or the percent distribution by age and sex Pyramid percent The pyramid display always shows two pyramids If you are using a single projection then the pyramid on the left will always be for the base year You can change the year for the pyramid on the right by clicking one of the buttons at the bottom of the screen to advance the pyramid one year Next show the previous year Previous show the first year First year or show the last year Last year If you have two projections loaded then the pyramid on the left will display the first projection and the one on the right will show the second projection Both pyramids will display the same year using the Next and Previous buttons will change both pyramids aD If you have more than two projections loaded you will be asked to choose which two pyramids should be shown before the pyramids appear 4 Demographic Summary Table The final display available in DemProj is a summary table showing
31. Survey ASFRs Bangladesh BFS 1989 reference fertility schedule BFS 1989 A births per thousand women 20 24 25 29 30 34 35 39 40 44 45 49 age group 1989 BFS TFR 6 TFR 5 x TFR 4 TFR The Coale Trussell model is recommended for populations whose initial fertility distributions do not resemble any regional pattern or have some idiosyncrasy It performs best in the medium run if moderate levels of fertility are targeted or in the short run regardless of levels of fertility But it gives too peaked results when low levels of fertility are projected after a substantial period of fertility decline C Mortality The best source of information on life expectancy will usually be national reports prepared by analyzing large scale surveys or censuses Mortality is described in DemProj through two assumptions life expectancy at birth by sex and a model life table of age specific mortality rates 1 Life Expectancy at Birth Base Year Estimates Life expectancy at birth is the average number of years that a cohort of people would live subject to the prevailing age specific mortality rates It is a useful measure that summarizes in one indicator the effect of age specific mortality patterns Life expectancy can be calculated from vital statistics on deaths if reporting is complete In the developing world death registration is not usually complete enough
32. a 0 97 Oman 1 05 Average 0 71 Egypt 0 49 Paraguay 0 38 El Salvador 0 35 Nicaragua 0 49 Upper Philippines 0 50 Honduras 0 62 Middle South Africa 0 50 Average 0 59 0 58 Average 0 54 Lower Middle India 0 35 Ghana 0 70 Bolivia 0 48 Congo Zimbabwe 0 60 Senegal 0 66 Zambia 0 20 Nigeria 0 46 Morocco 0 55 Pakistan 0 35 Guatemala 0 47 Mauritania 0 10 Kenya 0 80 Lesotho 0 38 Cameroon 0 60 Average 0 19 China 0 12 Average 0 52 C te d Ivoire 0 70 Indonesia 0 40 Average 0 49 Lower Vietnam 0 80 Middle Average 0 52 0 46 Low Bangladesh 0 45 Mali Uganda Benin 0 40 Tanzania 0 40 Malawi 0 30 Ethiopia 0 30 Nepal 0 30 Niger Mozambique 0 30 Average 0 23 Central Madagascar 0 10 African Chad Republic 0 30 Yemen 0 50 Haiti 0 40 Laos 0 50 Average 0 20 Sudan 0 40 Cambodia 0 20 Low Average 0 30 0 27 Overall Average 0 49 0 44 0 44 0 28 0 41 continued Program Effort 1994 1999 SocioeconomicS Very Weak Overall etting Strong Moderate Weak None Average Low Bangladesh 0 45 Mali Uganda Benin 0 40 Tanzania 0 40 Malawi 0 30 Ethiopia 0 30 Nepal 0 30 Niger Mozambique 0 30 Average 0 23 Central Madagascar 0 10 African Chad Republic 0 30 Yemen 0 50 Haiti 0 40 Laos 0 50 Average 0 20 Sudan 0 40 Cambodia 0 20 Low Average 0 30 0 27 Overall Average 0 49 0 44 0 44 0 28 0 41 Source Ross and Stover 2001 2 The Age Distribution of Fertility In addition to the TFR the age distribution of fertility is also required to make a population projection
33. ables provide five year survival ratios the proportion of a five year age group that survives to the next five year age group five years later These five year survival ratios are converted to single year survival ratios by taking the fifth root of the five year survival ratio The result is used as the survival ratio for alll five ages in the corresponding age group C Migration The net number of migrants during a particular year for each age and sex group is determined as the total number of migrants for that sex in the previous year multiplied by the proportion that are in the corresponding five year age group divided by five The distribution of migrants is entered for five year age groups These are divided by five to estimate the number of migrants at each single age within the five year age group D Deaths The number of deaths occurring during the year to persons of a particular age and sex at the beginning of the year are calculated as follows deathsast 1t POPatsti Migratst1 2 1 Srast where deathsastit deaths occurring as people age from age group a at time t 1 to age a at time t POPas t the population of age group a and at time t Migra 1 s t 1 the net number of migrants of age group a l at time t 1 S a s t the survival ratio or proportion of the population of age group a and sex s at time t 1 that survives to age group a at timet nn E Population Size The population of
34. all the demographic indicators You can scroll through this page to see all the output If you have more than one projection loaded the indicators for the second projection will immediately follow the first To print a table select File from the menu bar and Print from the pull down menu G Saving the Projection It is always a good idea to save the projection to your hard drive whenever you make a change to any assumptions To save the projection without changing the name choose File from the menu bar and Save projection from the pull down menu To save the projection with a different name choose File from the menu bar and Save projection as from the pull down menu You will then have a chance to specify a new file name for the projection Normally when you save the projection with a new name you should also change the projection title This will avoid confusion if you have both projections loaded at the same time H Opening an Existing Projection If you have already created a DemProj projection or are using a projection provided by someone else you can immediately load that projection 1 Select File from the menu bar 2 Select Open projection from the pull down menu 3 Select the file you wish to use and click the Ok button to open the projection You can open more than one projection at a time Just repeat these steps to load a second or third projection When
35. and have the computer calculate numbers for the intervening intervals Multiply to multiply a cell column or row by a specific number and Source to write notes indicating the source of the data for future reference To use the Duplicate button 1 Highlight select the range column row or cells to be affected The first cell in the range should be the value you want to copy 2 Extend the range to the last year by using the mouse hold down the left button and drag the range or the keyboard hold down the shift key and use the arrow keys 3 Click on the Duplicate key to copy the value at the beginning of the range to all the other cells in the range To use the Interpolate button 1 Enter the beginning and ending values in the appropriate cells Highlight the entire range from beginning to end Click on the Interpolate key to have the values interpolated and entered into each of the empty cells To use the Multiply button 1 Highlight the range column row or cells to be affected 2 Enter the multiplier in the dialogue box 3 Click Ok to accept The entire range will be multiplied by the designated number 46 re DemProj does have range limits built into the individual editors For example the model will accept estimates of life expectancy between 32 5 and 87 5 If you enter a value such as 125 you will be prompted to change the number To use the
36. and females increases by 2 0 to 2 5 years over each five year period when life expectancy is less than 60 and then increases at a slower rate at higher levels Table 4 shows the working model used in the United Nations population projections EBJ Table 4 UN Working Model of Life Expectancy Improvement During a Five Year Period Initial Life Fast Rise Middle Rise Slow Rise Expectancy Male Female Male Female Male Female 55 0 57 5 2 5 25 2 5 25 2 0 2 0 57 5 60 0 2 5 2 5 2 5 2 5 2 0 2 0 60 0 62 5 25 25 2 3 25 2 0 2 0 62 5 65 0 2 3 2 5 2 0 2 5 2 0 2 0 65 0 67 5 2 0 2 5 1 5 2 3 1 5 2 0 67 5 70 0 1 5 2 3 1 2 2 0 1 0 1 5 70 0 72 5 1 2 2 0 1 0 1 5 0 8 1 2 72 5 75 0 1 0 1 5 0 8 1 2 0 5 1 0 75 0 77 5 0 8 1 2 0 5 1 0 0 3 0 8 77 5 80 0 0 5 1 0 0 4 0 8 0 3 0 5 80 0 82 5 0 5 0 8 0 4 0 5 0 3 0 3 82 5 85 0 0 5 0 4 0 3 85 0 87 5 0 5 0 4 0 3 2 Life Expectancy and AIDS In a number of countries the AIDS epidemic has had a significant impact on mortality It affects both life expectancy and the age and sex pattern of mortality This health concern raises two problems for population projections First in countries with high HIV prevalence the future course of the AIDS epidemic will be the single largest determinant of future life expectancy Second the age pattern of mortality will depart significantly from the patterns described in the model life tables discussed below Therefore in countries with adult HIV prevalence greater than a f
37. ard disk space To install the Soectrum program follow the directions below 2 Installing from floppy diskettes Insert the first diskette into your disk drive Select Start from the task bar Then select Run from the pop up menu In the dialogue box that appears type the file name a Specinstall exe and press Ok If the install disk is in floppy disk drive b then use the file name b Specinstall exe Follow the instructions on the screen to complete the installation Installing from a CD ROM Insert the CD ROM into your CD ROM drive The installation program should start automatically If it does not Select Start from the task bar then select Run from the pop up menu In the dialogue box that appears click on Browse and find the file Specinstall exe Then press Ok Installing from the internet Start your internet browser and go to www FuturesGroup com Click on Software and then Spectrum Next click on Spectrum download single executable file From the dialogue box that appears next select Save Select a location for the file Once the file has been downloaded click on that file and the follow the instructions C Creating a New Projection 1 Starting the Spectrum Program To start Soectrum b Click the Start button on the task bar c Select Programs from the pop up menu d Select Spectrum from the program menu Alternatively
38. ban and rural projection enter the urban population size by age and sex If you are not including urban and rural projections these columns will not be displayed 3 Check to be sure that the total male and female populations are correct once you have entered alll the required information If they are not you have probably entered a number incorrectly in one or more of the cells a 4 Once all the data are entered correctly click on the tab Total fertility rate to move to this editor Total Fertility Rate This editor is used to enter the base year total fertility rates TFRs and the assumed future TFRs The first few years will be shown on the screen To use this editor 1 Click somewhere inside the editor to make the scroll bar appear 2 Scroll to the right or left to see all the years 3 Enter a TFR for every year of the projection Spectrum lef x File Edit Display Options Window Help Demographic data SAMPLE Edit First year population Model lfe table 3 Total fertility rate 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 TFR 380 370 360 350 340 330 320 310 300 290 Ok Cancel Duplicate Interpolate Source Ready 0 SAMPLE If you want to keep the TFR constant at the base year value you can enter the base year value and then use the Duplicate key duplication may be done for any interval of time To duplicate
39. ban logit Next we assume that the logit of the percent of the 10 14 age group that is urban will increase by the same amount logit 10 14 urban in 1985 logit 10 14 urban in 1980 IUL The logit is then transformed back into a percentage and the size of the 10 14 urban age group is calculated A 10 14 urban e2 logit 10 14 urban 2 logit 10 14 urban urban pop 10 14 total pop 10 14 10 14 urban These calculations are carried out for each age group Then all the age groups are normalized to sum to the total urban population The size of the rural age groups is simply the size of the total age group minus the size of the urban age group Vi e References Barkalov N B 1984 Modeling the Demographic Transition Moscow Moscow University Press Barkalov N B and S Kirmeyer n d 1989 New Shapes for Fertility Analysis Unpublished Beers H S 1945 Six Term Formula for Routine Actuarial Interpolation The Record of the American Institute of Actuaries 34 Part 69 59 60 Bos E My T Vu E Massiah and R A Bulatao 1994 World Population Projections 1994 95 Edition Baltimore John Hopkins University Press Coale A J P Demeny and B Vaughan 1983 Regional Model Life Tables and Stable Populations Second Edition New York Academic Press Coale A J and T J Trussell 1974 Model Fertility Schedules Variations in the Age Structures of Childbearing i
40. be nn If a box is shown in gray you will not be able to change its contents It means that another projection has been loaded and the data must remain the same If you want to create an entirely new projection you should close the other projections using File and Close and then select File and New Users may want to have several projections open in order to examine the effects of changing assumptions such as the final year total fertility rate Once all the information is entered for this dialogue box click on the Ok button You can always return to this screen and change some of the information by selecting Edit from the menu bar and Projection from the pull down menu more than eight characters in length and should not contain any illegal characters you may use letters numbers and certain symbols such as a hyphen Do not enter an extension with the file name the program will automatically assign the extension pjn to the projection file 1 Click on the Projection file name button to open an edit box and type the file name 2 Click on Ok to accept or Cancel to reject First year Click in the First year box to enter the first year of the projection Final year Click in the Final year box to enter the final year of the projection In most cases the final year should not be more than 50 years later than the first year However i
41. ber of live births per 1000 women in the age group rather than as the percent distribution of fertility Data on age specific fertility rates can be converted to the required percentage distribution by dividing each age specific fertility rate by the sum of all the age specific fertility rates This calculation is illustrated in Table 2 Table 2 Calculation of the Distribution of Fertility by Age Group from Age Specific Fertility Rates Age Age Specific Fertility Percent Distribution Group Rate for Fertility by Age Group 15 19 84 10 9 20 24 202 26 3 25 29 203 26 4 30 34 143 18 6 30 34 97 12 6 40 44 34 4 4 45 49 5 0 7 Total 768 100 0 From a review of hundreds of fertility shapes we know that fertility patterns tend to concentrate and to shift to younger years as fertility declines Horne and El Khorazaty 1996 In Figure 1 for example the normalized fertility distributions for Bangladesh show a switch from a traditional plateau distribution in 1975 to a rather peaked distribution in 1993 94 For Taiwan Figure 2 shows a shift from a homogenous distribution to one where fertility occurs almost entirely among women in their twenties nn Figure 1 Shift in Fertility Distributions Bangladesh 1975 to 1993 94 5 percent distribution 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group 1975 BFS 93 94 DHS Figure 2 Shift in Fertility Distributions Taiwan 1956
42. consistent with the national goals for these other indicators 3 Published projections The population projections prepared by the United Nations Population Division and reported in World Population Prospects include three assumptions low medium and high about future fertility for each country included in the report These fertility assumptions may be used The disadvantage to using these projections is that it is not clear how the low medium and high assumptions have been determined but the UN generally considers the medium variant to be the most likely The U S Census Bureau projections also contain a set of TFR assumptions 4 Recent trends and international experience If information is available on the TFR for several years it may be useful to analyze the trends in TFR and to develop a future assumption based on continuing past 1 However if the population projection is combined with a family planning projection then the future value of the TFR may be determined by the impact of the family planning program as determined by the FamPlan module See FamPlan s user s manual for instructions ee S trends It should be noted however that past trends cannot be expected to continue for very long into the future TFR rarely declines at a constant pace throughout an entire demographic transition Rates of decline are often slow at first increase during the middle of the transition and slow again as th
43. cy for each year or five year interval in the first row and the corresponding survival rates in the rows below The life expectancy values do not need to be round numbers nor do they need to be equally spaced however they do need to be arranged from the lowest value in the first column to the highest value in the last column Once the new values are entered save the table as a text file using a unique name and then specify the custom table and enter this name when creating the DemProj projection file D Migration Migration refers to the number of migrants moving into or out of the area for which the population projection is being prepared If the projection is for a country then it is international migration If the projection area is a region or city then migration refers to people moving into or out of the region or city 34 In most cases information on migration will come from local sources usually studies based on a national census Age and sex patterns of migration vary considerably Migration is specified through two inputs The first is the net number of migrants by sex and year If the net flow is outward then net migration should be a negative number If the net flow is inward then it should be positive In most cases information on migration will come from local sources usually studies based on a national census The United Nations report World Population Prospects does contain estimates and projections of
44. dying qx The probability that an individual or group of individuals having lived to exact age x will die before reaching exact age x 5 Probability of survival sx This term is the complement to the probability of dying It refers to the probability that an individual who has reached exact age x will go on to live to exact age x 5 Pull down menu A menu opened by clicking on key words at the top edge of the screen Pull down menus allow users to select operations Quinquinnial Five year age groups The basis for most cohort component projections is five year age groups over five year intervals Radio button These buttons emulate raised buttons on early radios which were punched to select radio stations The graphically portrayed raised radio buttons on interfaces permit users to select among at least three alternatives Rate of natural increase RNI The rate at which the population is increasing or decreasing in a given year due to the surplus or deficit of births over deaths expressed as a percentage of the base population Semi log graph A graph of data points for which one axis is graduated logarithmically and the other is not almost always being arithmetic instead Sex ratio The number of males per 100 females in a population Survival ratio The proportion of the population of a particular age that survives to the next age in the next year Synthetic hypothetical cohort A cross section of the popula
45. e 22 Figure 7 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs Bangladesh BES 197d sociation sit ohada elena hiaiotlon wie E A a Jelwaiolied dl 24 Figure 8 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs Bangladesh BES 98S vs cest cesiastty Molssaietal a AN dalegstanseglives Wa A A ENA 24 Figure 9 Model Life Table Mortality Probabilities Coale Demeny West Female Models Table Compared by Level of life EXOECTENGCY sonrscusinaunaninon iunii ea seuss Sea oath Som boosted sande lebss 30 Figure 10 Model Life Table Mortality Probabilities Coale Demeny Female Model Table Families Comparison by Family at e 0 45 we ccsssscsesssssecsecsscsscesceeesscsscsseeeeseecsacsaeeseenseeaes 31 Figure 11 Model Life Table Mortality Probabilities United Nations Female Model Table Families Comparison by Family at 0 45 oina haa e Eat 32 Figure 1 22 TYPICAl PGE M OF UMOGMIZATION sii sic esis els basics A AA A 36 Figure 13 Fertility Distribution by TFR UN Sub Saharan Africa Pattern wee ccccccseesecseececesseeeseeseeeees 73 Figure 14 Fertility Distribution by TFR UN Arab PAHE en eee escessessceseeseeseceeceseesecseceeceseeaecsecesenceaecseeeeeaes 74 Figure 15 Fertility Distribution by TFR UN Asia Pattern ou ce eeeeseesseeseeceeseesseecceceesecsecseceseesecseceeeeesecseeeeenes 74 Figure A 1 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs Bangladeshi BES 1975 ces uinna a A id Sae
46. e United Nations families again for females with a life expectancy at birth of 45 years There is greater differentiation between United Nations than between Coale Demeny families One extreme is given by the East Asian pattern which has a rather high level of adult mortality and a relatively low level of under age 10 mortality The other extreme is the South Asian family which has a distinctly low adult mortality pattern between ages 10 and 50 anda relatively high child mortality pattern Figure 11 Model Life Table Mortality Probabilities United Nations Female Model Table Families Comparison by Family at e 0 45 j probability of dying 40 50 60 70 80 age group Chile South Asia Latin America x General e East Asia Selecting a Model Life Table There are several approaches to determining the most appropriate life table for a particular country or region in terms of the mortality level and pattern 1 The best way is to compare data on age specific mortality for that country with the mortality pattern at the corresponding level of life expectancy for each of the model tables The appropriate table will be the one that most closely matches the actual experience Bo 2 The best model life table may already have been determined by demographers from that country Consulting with them or reviewing reports or official projections may indicate the model table that the national demographer
47. e to all stakeholders poeepra Meta U Modeling can concentrate on favored goals and stakeholders A 3 objectives and demonstrate how they are assisted by the proposed policies That few things in life operate in a linear fashion A straight line rarely describes social or physical behavior Most particularly population growth being exponential is so far from linear that its results are startling Modeling shows that all social sectors based on the size of population groups are heavily influenced by the exponential nature of growth over time That a population s composition greatly influences its needs and its well being How a population is composed in terms of its age and sex distribution has broad ranging consequences for social welfare crime rates disease transmission political stability etc Modeling demonstrates the degree to which a change in age and sex distribution can affect a range of social indicators The effort required to swim against the current A number of factors can make the success of a particular program harder to achieve for example the waning of breastfeeding in a population increases the need for contraceptive coverage Modeling can illustrate the need for extra effort even if simply to keep running in place o gt C Organization of the Model Manuals D The POLICY Project is implemented by the Futures Group in collaboration with Research Triangle Institute RTI and
48. ed salts Aiton alee A 6 Figure A 2 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs List Bangladesh BES W989 sed suisse salsa oh vaaetl ial vend ialvihs ia ee Sneeth false bas Pak des ne Sel seed sialic A 6 of Tables Table 1 Declines in TFR in 1990s by Level of Program Effort During 1994 1999 and SOGIOSCOMOMICS STN Qicsyute se ccuadsrteenedsgeevyedeanscad aa a a a a aah vlads 15 Table 2 Calculation of the Distribution of Fertility by Age Group from Age Specific Fertility RATES oe r wisheadas geet T A d tala EE O E a data e E A E a SS 17 Table 3 UN Model Tables of the Age Distribution of Fertility ccc cccccescessesscsecescesececseceseeseesseseesees 19 Table 4 UN Working Model of Life Expectancy Improvement During a Five Year Period ss 27 Table A 1 Coale Trussell Fertility Control Schedule Vx ccccseesscsscescescessesecesceseesscseceecessesecseceecesseseeneeeeess A A Table A 2 Bangladesh ASFRs from Various Surveys and Projected RATES ceccssesecsscesceeeesesseeseees A 7 i e Introduction A Description of the Spectrum System Spectrum consolidates DemProj FamPlan Benefit Cost AIM and RAPID NewGen and PMTCT models into an integrated package 1 Components POLICY and its predecessor projects have developed computer models that analyze existing information to determine the future consequences of today s development programs and policies The Spectrum Policy Modeling
49. eighted averages Weighting will be done by an appropriate population For example the TFR for the aggregate population will be calculated as the weighted average of the TFRs for each of the input projection weighted with the number of women of reproductive age 15 49 To use this feature follow these steps 1 Select File and Aggregate from the Spectrum menu Note this command not available if you have any opened projections If the command is not available first select File and Close and close all projections 2 Click the Add button to select the projection files to be aggregated You can select as many files as you want Once you have selected all the projection files you can save the list if you may want to use it again by clicking the Save button To remove files from the list click Remove If you have previously created a file list you can use it by clicking the Open button and selecting the file 3 Once you have the files you want to aggregate click Process Spectrum will read each of the files in the list and create a new file Soecify a name for the new file 4 Once you have completed processing and provided a new file name click the Close button 5 You can now load the new file you just created and examine any of the DemProj indicators V Methodology DemProj calculations are based on the standard cohort component projection modified to prod
50. emography Select the type of file you wish to create a RAPID file or an AIM file Specify the file name The projection will then be saved in a special format that can be read into the Excel versions of RAPID K Importing a Demographic Projection Produced with an Earlier Version of DemProj If you have a demographic projection that was produced with an earlier version of DemProj DemProj 3 or DemProj 4 for DOS you can import that projection file into Spectrum 1 2 Select Import from the pull down menu Select Demography from the next menu You will see a dialogue box asking for the name of the file you wish to import You will initially see a list of DemProj 4 files To import a DemProj 3 file click on the down arrow under the label List files of tyoe and select DemProj 3 from the list Then you can select DemProj 3 files Select File from the menu bar Select the file you wish to import and click the Ok button The file will be read in and converted to Spectrum format 66 P L Aggregating projections If you want to add together several projections to produce a total for a region you can do that with the Aggregate function This function will read the projections you specify and combine then into a single projection file All number indicators referring to numbers of people will be added across all projections Rates such as TFR and life expectancy will be calculated as w
51. ency virus IMR infant mortality rate NRR net reproduction rate RAPID Resources for the Awareness of Population Impacts on Development project RNI rate of natural increase TFR total fertility rate U5MR under five mortality rate UN United Nations USAID United States Agency for International Development WFS World Fertility Surveys a a Appendix A The Coale Trussell Relational A 1 Fertility Model Description of the Model This model first introduced in 1974 Coale and Trussell 1974 1978 United Nations 1983 is the most widely used model of the age composition of fertility The model decomposes age specific fertility rates into three factors corresponding to basic fertility determinants natural fertility hypothetical fertility that might exist in the absence of birth control if all women were in sexual unions during their entire reproductive spans birth control deliberate control over childbearing by way of contraception and or abortion cohabitation consensual or marital time soent by women within sexual unions with time in unions being shortened due to premarital sexual abstinence spousal separation or dissolution of the union The model formalizes the relationship between age specific fertility and its determinants in a very simplified form Barkalov and Kirmeyer n d 1989 It assumes that natural fertility within unions is proportional to a certain age schedule that is approximately the
52. er 1 000 population in a given year Deaths The total number of annual deaths Defined age group The size of the population in a user defined age group Dependency ratio The ratio of the economically dependent part of the population those aged 0 14 and 65 and over to the productive part those aged 15 64 Doubling time The number of years it would take for the population to double its current size at the current annual rate of growth a Gross reproduction rate GRR The average number of daughters that would be born to a woman or a group of women during her lifetime if she passed through all her childbearing years conforming to the age specific fertility rates of a given year This is similar to the TFR except that it counts only daughters Infant mortality rate IMR The number of deaths to infants under one year of age per 1 000 live births Life expectancy e 0 The average number of years a person can expect to live based on the age specific death rates for a given year This is the calculated life expectancy at birth If AIM is not being used then this number will be the same as the input life expectancy However if AIM is being used then the calculated life expectancy will include the impact of AIDS deaths Therefore it will be different from the input life expectancy Mean age of childbearing The average age of mothers at the time of birth Median age The age that divides a
53. es click on the Selected button It will display a table of values for all years in the projection File Edit Display Options Window Help Demographic data SAMPLE Comparison Ok Cancel Ready 0 SAMPLE To see the values as a graph 1 Click on the Chart button This will show a graph of first year and last year values not shown 2 To close the graph click on the X icon in the upper right part of the graph window Windows 95 or the icon Windows 3 1 3 Click the Close button to return to the editor To compare the age specific fertility distribution that would result from selecting any of the UN or Coale Trussell model tables 1 Click the Comparison button to see a table comparing the age specific fertility distribution This table will show the base year 52 2 Advance the table by clicking the Next Year button or return to earlier years by clicking the Prev Year button 3 To see a graph instead of a table click the Chart button see screen below 4 To close the graph click on the X icon in the upper right part of the graph window Windows 95 or the icon Windows 3 1 5 Select Close Spectrum File Edit Display Options Window Help Demographic data SAMPLE 1990 TFR 3 80 15 19 20 24 25 29 30 34 35 39 40 44 45 49 Saharan Arab Asia Avg Ready w SAMPLE
54. eted Therefore it is important to be sure that corrected census figures are used whenever possible rather than raw census tables There are other sources of population data if recent census reports are not available The Population Division of the United Nations publishes a considerable amount of population data The most useful sources for population projections are the Demographic Yearbook which contains the most recent census data for most countries and the World Population Prospects published every two years and containing population estimates and projections for most countries of the world The latest edition of World Population Prospects may be a particularly useful source if country data are unavailable since it will contain estimates 10 Internet sites may provide the latest population estimates from several sources of base year populations as well as assumptions about future levels of fertility mortality and migration World Population Prospects contains estimates and projections of population by five year age groups that have been adjusted for misreporting These data may be used when reliable census data are not available Data files prepared using EasyProj described below in Section IV C 2 use data from World Population Prospects The U S Census Bureau also publishes a set of population projections for the countries of the world called World Population Profile Other sources such as the Population Reference Burea
55. ew percent it is best to consider the effects of AIDS explicitly in the population projection These effects cannot be incorporated simply by changing the life expectancy assumption since the age pattern of mortality is also affected AIDS deaths are concentrated in the age groups of 15 49 The recommended approach is to first develop a population projection that ignores the effect of AIDS then to make assumptions about the future level of adult HIV prevalence and let the computer program calculate the effects of AIDS on the population projection Such projections can be prepared using DemProj and AIM the AIDS component of Spectrum The methods and assumptions to do this are described in a companion manual AIM A Computer Program for Making HIV AIDS Projections and Examining the Social and Economic Impacts of AIDS ee It should be noted that the life expectancy assumptions reported in World Population Prospects and World Population Profiles include the effect of AIDS Most of the steps required to prepare a population projection that excludes the effects of AIDS are the same as for any other projection However preparation of the life expectancy assumption may be different If AIDS has not yet contributed significantly to mortality then estimates of current life expectancy can be used However in many countries AIDS has already affected life expectancy In these cases it is necessary to prepare an estimate of life expectancy that e
56. ey approach replacement level fertility Socioeconomic development and population program effort Studies have shown that the pace of fertility decline is related to the level of socioeconomic development of a country and the amount of effort put into the family planning program These studies are summarized in Table 1 which shows the decline in the TFR as a function of these two factors This experience can be used to develop realistic assumptions about the rate at which fertility could decline in the future in any given country Table 1 shows that the most rapid fertility declines experienced between 1978 and 1990 were for countries with strong family planning programs and high levels of socioeconomic development during the 1980s Table 1 Declines in TFR in 1990s by Level of Program Effort During 1994 1999 and Socioeconomic Setting Program Effort 1994 1999 Overall Socioeconomic Very Averag Setting Strong Moderate Weak Weak None e High Mexico 0 37 Chile 0 10 Brazil 0 25 Costa Rica 0 36 Mauritius 0 24 Trinidad 0 45 Uruguay 0 09 Colombia 0 21 and Tobago Venezuela 0 31 Jamaica 0 26 Panama 0 08 Argentina 0 21 Korea Rep 0 18 Uzbekistan 0 72 Kazakhstan 0 36 Malaysia 0 36 Average 0 34 Average 0 27 High Average 0 27 0 28 Upper Middle Tunisia 0 81 Dominican 0 28 Ecuador 0 42 Guyana 0 10 Sri Lanka 0 30 Republic Namibia 0 45 Mongolia 0 70 Tran 1 80 Syria 0 79 Lebanon 0 54 Average 0 40 Peru 0 50 Turkey 0 40 Jordan 0 76 Thailand 0 15 Algeri
57. f Soectrum is being used only to make a population projection e g no other modules will be used then projections up to 150 years in length may be made Projection timeframe The radio button or option labeled Standard demographic projection lt 50 years will be selected by default This is the normal mode of operation However if you wish to make a population projection longer than 50 years then you may select the button for Demography projection gt 50 years This choice will cause the DemProj module to make the population projection in five year intervals rather than in single years In this case a projection up to 150 years in length may be made Active modules These radio buttons or options let you select other Spectrum modules that will be used with the population projection If none are selected then only a population projection will be made Alternatively you may select any or all of the other modules to be included with your projection EasyProj EasyProj is a special feature that allows you to use data prepared by the United National Population Division and published in World Population Prospects If you click on the EasyProj button the program will prompt you to select a country and ask whether you want to use the UN low medium or high projection assumptions Once you click OK the program will load the base year population the total fertility rate the male and female life expectancy and the model
58. f the population those aged 0 14 and 65 and over to the productive part those aged 15 64 Dialogue box A box permitting users to choose among a limited number of options The box is accompanied by text elaborating upon those options Doubling time The number of years it would take for the population to double its current size at the current annual rate of growth Fifth root The fifth root of the number n is the number which multiplied by itself five times exactly equals n For example the fifth root of 243 is 3 3x3x3x3x3 Gross migration The total number of people who move to and depart from an area Gross reproduction rate GRR The average number of daughters that would be born to a woman or a group of women during her lifetime if she passed through all her childbearing years conforming to the age specific fertility rates of a given year This is similar to the TFR except that it counts only daughters Infant mortality rate IMR The number of deaths to infants under one year of age per 1 000 live births Initial age distribution The age sex distribution at the beginning of a projection period Interpolation Given two numbers that serve as boundary points it is possible to estimate the values that lie at intervals between the two points For example if the total fertility rate for a country or region was actually measured only in 1980 and in 1995 by assuming even increments from year to year it i
59. f urbanization Whenever at least three variables are involved such as two forces and one outcome a computerized model can both reduce the burden of manipulating those variables and present the results in an accessible way Some of the policy issues commonly addressed by the Spectrum set of models include The utility of taking actions earlier rather than later Modeling shows that little in a country stands still while policy decisions are stalled and that many negative outcomes can accumulate during a period of policy stasis The evaluation of the costs vs the benefits of a course of action Modeling can show the economic efficiency of a set of actions i e whether certain 2 outcomes are achieved more effectively than under a different set of actions or simply whether the cost of a single set of actions is acceptable for the benefits gained The recognition of inter relatedness Modeling can show how making a change in one area of population dynamics such as migration rates may necessitate changes in a number of other areas such as marriage rates timing of childbearing etc The need to discard monolithic explanations and policy initiatives Modeling can demonstrate that simplistic explanations may bear little relationship to how the real world operates A set of policies under The utility of door openers A set of policies under consideration may not be consideration may not be acceptabl
60. fe Tables for Developing Countries Department of International Economic and Social Affairs Population Studies No 77 New York United Nations United Nations 1977 World Population Prospects as Assessed in 1973 Department of Economic and Social Affairs Population Studies No 60 New York United Nations United Nations 1974 Methods for Projections of Urban and Rural Population Manual VIII New York Department of Economic and Social Affairs United Nations U S Bureau of the Census 1994 World Population Profile 1994 Washington DC U S Bureau of the Census Van de Walle E and Henry L 1982 Multilingual Demographic Dictionary International Union for the Scientific Study of Population IUSSP Li ge Belgium Ordina Editions VI f e Glossary of Terms Many of the following terms were obtained from the Population Reference Bureau s Population Handbook 1989 others were adapted from the International Union for Scientific Study of Population s IUSSP s Multilingual Demographic Dictionary Van de Walle and Henry 1982 Age specific fertility rate ASFR The number of births in a year for a population of a given age and sex to the mid year population of that same sex and age group Annual growth rate GR The rate at which the population is increasing or decreasing in a given year due to natural increase and net migration expressed as a percentage of the base population ASCII text file A file of te
61. grAM seesssssssesssseesseessreeseeessreeseressreessreeseress 40 2 Specifying the Projection Parameters in Projection Managet 41 D Entering the Base Year Data and Projection Assumption 66 43 1 Specifying New Demographic Projection ParaMeters ceeeeeee 43 2 Entering the Base Year Data and Projection Assumptions 5 45 3r ABOTIR EAO nieur ann oud a a aae ol ule A 46 First Year POPUIAHON sesesessessessesessesseeseesseeseesreseestessessessresteseestestestestestsstestestesresessee 47 Total Fertility RTOS p5c2 5 8s 6ates cua dasaa chieltasv seh woke ToaseSacastesengla ada teopiadaa dust sastacnaglaletaesotoin amp 48 ASFR 49 SexRatioat Bi Hicradactniuastaat cnstans tat co scitniieadant A A A dal 54 SEXO SCTONCY nainen antan a A Oa N a a aa tees 55 Modellife tablesennonan nna an Aa a elena 57 International WGN ss ssesssesssesssesserstesrsssresteeteseresttesttesressitssretreseresrtesrtssresrressre 58 REGIONE ASSUMPTION Sasan a a A a A Rhee 58 4 Leaving the Demographic Data Editors scccssesccesssecessrscesssceenees 59 5 Saving the Input Data essseesseessseesserssserssecesseesseessserssreessereseesseressersseressee 59 E Making the Projection cccccccccssssssssssscccccccccecessssssscecccceeeeeeessssseeseeees 59 F Examining the OU U a e a aa eea io akioa 60 Te Graphs GHG Bar MONS eaa A in A E RA a 63 2 NODES enei ne ee EE A Sa aia E a hue aS 63 3 Displaying All
62. ibution that takes advantage of both methods To get the most out of this method the interpolation for any particular year should be based on how much the TFR has changed within the projected range and not on the year itself The Coale Trussell Fertility Model Another approach to using model fertility shapes in DemPro is to use the Coale Trussell model Coale and Trussell 1974 and 1978 This model takes into account the change in marriage patterns the degree of fertility control and the underlying natural fertility of a population The main feature that makes the model of interest to DemProj is that it is relational users supply an initial age distribution and desired future total fertility rate and a new age pattern of fertility is generated which takes the characteristics and components of the initial distribution into account Figures 7 and 8 show the shapes generated if we start with the rather different shapes of Bangladesh s 1975 and 1989 Fertility Surveys BFSs a Figure 7 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs Bangladesh BFS 1975 reference fertility schedule BFS 1975 A births per thousand women 250 200 150 100 50 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group 1975 BFS TFR 6 TFR 5 TFR 4 gt TFR 3 Figure 8 ASFRs Generated by Coale Trussell Model Compared with
63. idiosyncratic West The United Nations families name very specific regions Latin America South America Chile South Asia East Asia plus the generic General Several aspects of these model schedules are highlighted in Figures 9 through 11 In each the probability of dying during an age interval qx is plotted against age groups A semi log scale is used to highlight important differences In Figure 9 the probabilities of dying are generated for the Coale Demeny West model for females for five mortality levels The range in mortality levels is from very low e 0 35 to rather high e 0 75 In this series the effects of the changing mortality levels are most noticeable in the younger age groups Figure 9 Model Life Table Mortality Probabilities Coale Demeny West Female Models Table Compared by Level of Life Expectancy probability of dying 20 30 40 50 60 70 80 age group In Figure 10 the qx mortality probabilities are plotted for the four Coale Demeny regions for females having the same life expectancy at birth 45 years The North pattern has the highest death rates for infants and children the West has high death rates for age 15 and higher Figure 10 Model Life Table Mortality Probabilities Coale Demeny Female Model Table Families Comparison by Family at e 0 45 4 probability of dying In Figure 11 the mortality probabilities are graphed for the fiv
64. ies and you will see one final menu listing the indicators available in that category Select one of the indicators Then you will see the display dialogue box It will look something like the one shown below Configure Total population xii Total fed 9 C Urban s v Rural s C 2000 eee eereg i The exact choices available will depend on the indicator you have selected For Total population you can set the region to Total Urban or Rural if you are doing a regional projection The sex can be set to Both Male or Female The display interval will normally be in single years but you can change it to display every five or ten years if desired The chart type is also set through this dialogue box Click on the button next to the type of display you want Normally the display will show all the years in the projection However if you want to see only part of the projection you can change the final year by selecting a new final display year from the Final year list box Once you are satisfied with the type of display click the Ok button and the display will appear It will look something like the display shown below File Edit Display Options Window Help Total population 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 DPSAMPLE Ready C 0 DPSAMPLE All the projections that are currently in use will be displayed on the same graph
65. including anti retroviral treatment infant feeding options and delivery options 2 Software Description Spectrum is a Windows based system of integrated policy models The integration is based on DemProj which is used to create the population projections that support many of the calculations in the other components such as FamPlan Benefit Cost AIM and RAPID Each component has a similarly functioning interface that is easy to learn and to use With little guidance anyone who has a basic familiarity with Windows software will be able to navigate the models to create population projections and to estimate resource and infrastructure requirements The accompanying manuals contain both the instructions for users and equations for those who want to know exactly how the underlying calculations are computed B Uses of Spectrum Policy Models Policy models are designed Policy models are designed to answer a number of what if OARS WEG UPC questions relevant to entities as small as local providers of ese a reese Ae primary health care services and as large as international Hahcanbechantel ar development assistance agencies The what if refers to influenced by public policy factors that can be changed or influenced by public policy Models are commonly computerized when analysts need to see the likely result of two or more forces that might be brought to bear on an outcome such as a population s illness level or its degree o
66. is approach is illustrated in Figure 12 A complete description of the methodology used can be found in Section V G Figure 12 Typical Pattern of Urbanization o percent of population urban 75 100 125 150 175 200 time in years F Projection Outputs DemProj will calculate and display the population size by year Projections can be examined in terms of total population or population by age sex and region In addition a number of demographic indicators can also be displayed A complete list of indicators available is given below with definitions for those that are not obvious Many of these definitions are taken from the Population Handbook Population Reference Bureau 1989 a complete glossary is contained at the end of the manual DemProj indicators Total population size Population aged 0 4 Population aged 5 14 Population aged 15 64 Population aged 65 Total net international migration Annual growth rate GR The rate at which the population is increasing or decreasing in a given year due to natural increase and net migration expressed as a percentage of the base population Births The total number of annual births Child woman ratio The number of children under the age of five per woman of childbearing age 15 49 Crude birth rate CBR The number of live births per 1 000 population in a given year Crude death rate CDR The number of deaths p
67. ity and fertility information on the overall level of each process and its shape or age pattern For the sake of efficiency and quite often for accuracy the shapes age patterns of the three components are supplied by model schedules Demographic research has long observed and collected patterns of data Model schedules attempt to capture these patterns with as few parameters as warranted Such model schedules are then used to evaluate the quality of other demographic data to smooth schedules of fertility nuptiality migration or mortality to provide building blocks in estimating levels and trends of demographic processes and to forecast the behaviors of these processes in a population In this last application DemProj uses model patterns for two processes fertility and mortality Fertility Mortality 1 TFR 1 Life expectancy at birth 2 Age distribution of fertility 2 Age specific mortality These approaches are covered in Sections Ill B and Ill C below nn A Base Year Population Several types of problems can exist in raw census figures including underreporting age misreporting and undefined ages These problems should be corrected through standard demographic procedures and reported in later census reports All population projections must start somewhere The starting point is the number of people in the population by age and sex in the base year For both males and females the population is d
68. ivided into five year age groups from 0 4 to 75 79 There is also a final age group for those people aged 80 and older Base year population figures are available from a number of sources Usually the best source will be a national census Census reports always include tables showing the size of the population by age and sex Often these tables are available for the national level and for provincial or district levels Several types of problems can exist in raw census figures including underreporting age misreporting and undefined ages Census tables should be adjusted to minimize these problems Underreporting can occur for a variety of reasons For example occasionally certain geographic areas or social status groups are entirely or partially missed in the census Sometimes respondents intentionally misreport in order to avoid identifying military age males marriageable age females or family members that may affect the family s taxes Age misreporting can occur when ages are purposely or unintentionally reported incorrectly such as when ages are rounded to the nearest five year age group or when ages are unknown In most censuses there will also be a certain proportion of the population with age undefined These problems should be corrected through standard demographic procedures and reported in later census reports but in many developing countries these reports may not be done or may only appear many years after the census is compl
69. jection DemProj first projects the national population and then distributes it according to region It does not make a separate projection for each region The benefit of this approach is that separate estimates of TFR life expectancy and model life tables are not required The disadvantage is a lack of flexibility in fully specifying the differences between regions If this flexibility is important DemProj should be used to project urban and rural regions separately es 35 There are two methods for developing the urban and rural projections For the first the analyst provides an assumption about the percentage of the total population that is urban for each year of the projection Then rural population is simply the difference between the total and urban populations The second approach relies on a method developed and used by the United Nations Population Division This method assumes that the percentage of the entire population that is urban follows an S shaped curve Therefore the rate of urbanization will be slow at first accelerate when the percent urban reaches 30 70 percent and then slow down once urbanization reaches high levels This approach requires an estimate of the annual growth rates of the urban and rural populations in the base year and the size of the urban population by age and sex in the base year This information should be readily available from national censuses A typical pattern of urbanization generated by th
70. jection is to decide the most appropriate geographic area for the application 2 Determine the period of the projection Population projections start at some base year and continue for a certain number of years into the future The base year is often selected on the basis of data availability and is usually the year of the most recent census or large scale survey The number of years to project is determined by the use of the projection Planning activities generally focus on short term projections five years while projections used for policy dialogue often use a longer time horizon 10 30 years 3 Collect data Ata minimum base year data need to be collected for the number of people by age and sex the TFR and life expectancy at birth Since the population projection will only be as good as the data on which it is based it is worth the effort to ensure that appropriate and high quality data are collected and prepared before starting the projection A special feature of DemProj called EasyProj allows you to make a projection quickly using data from the United Nations World Population Prospects nn Make assumptions Population projections require assumptions about the future levels of the total fertility rate TFR life expectancy at birth and international migration Assumptions regarding the most appropriate model tables see Sections Ill B and Ill C for fertility and mortality are also required These assumptions should
71. l her childbearing years conforming to the age specific fertility rates and age specific mortality rates of a given year This is similar to the GRR except that it includes the effect of mortality that would cause some women to die before completing their childbearing years Normalized The transformation of a series of data points to a percent distribution summing to 100 percent Population aged 0 4 The portion of the population under age five It is often of interest as it may be subject to high mortality and consequently may require a large amount of health care relative to other age groups Population aged 5 14 The portion of the population which is generally considered to be of school age Population aged 15 64 The portion of the population which is generally considered to be of employment age en Population aged 65 The portion of the population which is generally considered to be of post employment age Population projection Computations depicting the future course of a population s size its structure and its interaction with dynamics such as fertility mortality and migration The projection is constructed based on assumptions about the future course of those population dynamics Population pyramid A graphic that portrays an age sex distribution It is so named because of its shape Pop up menu A menu from which users can select items or actions Pop up menus can appear anywhere on the screen Probability of
72. life table from the United Nations estimates and projections By default the projection will assume zero net migration 42 re D Entering the Base Year Data and Projection Assumptions 1 Specifying New Demographic Projection Parameters For readers who feel they need additional review or explanations of the terms found in this section Chapter Ill and the glossary to this manual may be useful To enter the assumptions for the population projection select Edit from the menu bar and Demography from the pull down menu A dialogue box like the one shown below will be displayed Demographic data SAMPLE The Projection parameters button lets you set the configuration of the projection Then you may enter the assumptions by selecting the Demographic data button First select the button labeled Projection parameters The screen should look like this File Edit Display Options window Help Projection parameters SAMPLE x First year 1990 Final year 2000 Projection period Single year Currency Name fi 995 US Dollars Scale Units C Include urbanjrural projection Thousands Urban Rural projection Do not include urban rural projection C Millions Cancel Ready 0 SAMPLE In the top left part of this box the first year final year and projection period are shown These entries cannot be changed here they are shown for information onl
73. n Human Populations Population Index 40 2 185 258 Coale A J and T J Trussell 1978 Technical Note Finding the Two Parameters That Specify a Model Schedule of Marital Fertility Population Index 44 2 203 213 Coale A J and J Trussell 1996 The Development and Use of Demographic Models Population Studies 50 469 484 Horne A Dale and M N El Khorazaty 1996 Childbearing and Bongaarts Indices for Coale Trussell s Model Fertility Schedules Genus LII 1 2 161 180 Jamison E and F Hobbs 1994 World Population Profile 1994 Washington DC U S Bureau of the Census Population Reference Bureau 1989 Population Handbook International Edition Second Edition Washington DC Population Reference Bureau ee Stover J 1994 DemProj A Demographic Model for Development Planning Version 3 Glastonbury CT The Futures Group International United Nations 1995 World Population Prospects The 1994 Revision Sales No E 95 XIll 16 New York United Nations United Nations 1993 World Population Prospects The 1992 Revision Sales No E 93 Xlll 7 New York United Nations United Nations 1989 World Population Prospects 1988 Department of International Economic and Social Affairs Population Studies No 106 New York United Nations United Nations 1983 Manual X Indirect Techniques for Demographic Estimation New York United Nations United Nations 1982 Model Li
74. nt of lifetime fertility 0 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group Sub Saharan Africa Arab Asia Average However regions are not as well associated with fertility patterns as they are with mortality patterns Mortality patterns by region have been employed long and successfully to analyze and project mortality Regional mortality forces that tend to match up with geography are climate country proximity culturally based sex roles diet medical practices political stability etc Fertility is subject to relatively more forces that are primarily not biological and therefore are harder to aggregate by geographic area than is true for mortality Figures 5 and 6 illustrate the inconstancy of regional patterns for projecting fertility They show that the Asia pattern was an adequate model for Bangladesh in 1975 when the TFR was 6 3 but by 1989 when the TFR had dropped to 5 1 the Asia model was far from adequate Bangladesh s status then was better matched by the sub Saharan Africa pattern nn Figure 5 Shift in Fertility Distributions Bangladesh and UN Asia Pattern 35 percent distribution A E Ae wN ny if Y 10 M SSA 5 4 SS 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group BFS 1975 ASIA TFR 3 ASIATFR 5 ASIA TFR 7 Figure 6 Shift in Fertility Distrib
75. ocioeconomic impacts of high fertility and rapid population growth RAPID DemProj was first produced in 1980 Since then it has been used by a large number of planners and researchers around the world It has been updated from time to time in response to comments and suggestions from users This current release DemProj 4 incorporates a number of new features in response to these comments DemProj and the entire Soectrum system is designed to produce information useful for policy formulation and dialogue within a framework of easy to use Computer programs The focus is on the generation of information useful for policy and planning purposes rather than detailed research into the underlying processes involved For this reason the programs are designed to be used by program planners and policy analysts DemProj uses data that are readily available and requires little demographic experience beyond the information available in this manual F Why Make Population Projections A discussion of the need for and impact of an expanded program of immunization requires a population projection to show the number of children who will need vaccination in the future and the reduction in morbidity and mortality rates that could be achieved by the proposed program Population projections are useful for a variety of purposes most commonly as a basis for planning For example assessing a nation s or region s needs for new jobs teachers
76. ollect data and make certain decisions before running the model For example to set the projection parameters you will need to decide The first year of the projection usually the latest year for which you have population data The last year of the projection Whether you want to project the total population or whether you want to break it down into urban and rural segments Whether you want to enter population numbers in terms of thousands or millions The data you will need include The first year population broken down by sex and in age categories of 0 4 5 9 etc until the final category of 80 Sex and age information in rural and urban categories for the first year if you want to break the projections down into rural and urban populations Total fertility rate Age specific fertility rates Sex ratio at birth the number of male births per 100 female births default is 105 Life expectancy for the first year male and female The model life table you want to use Net migrants per year by sex and age These inputs are all described in Chapter Ill of this manual RY B Installing the Spectrum Program The Spectrum program is distributed on floppy diskettes CD ROMS or through the Internet at http www FuturesGroup com It must be installed on a hard disk before it can be used Spectrum will operate on any computer running Windows 95 or later version It requires about 10MB of h
77. om the Bangladesh Fertility Survey of 1975 when Bangladeshi fertility was high and had the characteristic plateau shape see Figure A 1 of high fertility behavior The second set of reference fertility rates came from the Bangladesh Fertility Survey of 1989 following a substantial decline in fertility and transition to a peaked shape of fertility rates see Figure A 2 These empirical rates are given in the upper part of Table A 2 The results of the fertility schedule projection are rather different They allude to the key feature of this type of fertility model It is relational Thus the projected schedules bear a relationship to the components of the empirical reference schedule In the case of the 1975 schedule as noted above it has the typical plateau shape of high fertility countries But it is atypical in that the pattern has a leftward tilt with higher relative concentration than usual for younger aged fertility As a result the Coale Trussell projected pattern is more peaked at younger fertility than are the shapes generated with reference to the 1989 data Because they have fewer idiosyncrasies then the reference data of 1989 provide a good set of projections to use in matching the next round of data collected in Bangladesh Figure A 1 ASFRs Generated by Coale Trussell Model Compared with Survey ASFRs Bangladesh BFS 1975 reference fertility schedule BFS 1975 i births per thousand women
78. on assumptions about future levels of fertility mortality and migration Since these are simply assumptions it is often wise to consider low medium and high variants of each assumption so that the range of plausible projections can be determined Second when population projections are used for policy dialogue it is usually important to show how various rates of population growth would affect the projections For example an analysis of the impacts of population growth on education typically would include a high growth projection to show the magnitude of the problem under current conditions and a low growth projection to show how a slower growing population would put less pressure on the education system to meet national education goals MO il Steps in Making a Population Projection There are seven key steps in making most population projections The amount of time spent on each step may vary depending on the application but most projection activities will include at least these seven steps 1 Select geographic area Population projections are normally made at the national level However projections may also be made for other geographic areas such as urban areas capital cities provinces districts and catchment areas For example the trend toward decentralization of public programs in many countries has greatly increased the need for projections at the district and provincial levels The first step in making a population pro
79. period If this parameter were known then the projected age specific fertility rates could be uniquely generated and their values would always be non negative Target aggregate fertility the total fertility rate or TFR is represented as TFR _ fo a e a Table A 1 Coale Trussell Fertility Control Schedule vx Age Group Fertility Control Schedule 15 19 0 069 20 24 0 069 25 29 0 279 30 34 0 667 35 39 1 042 40 44 1 414 45 49 1 671 If the proposed TFR were not too small when compared to the original TFR the equation would have a unique solution permitting projection of fertility rates for a broad range of levels The solution could be found with any nonlinear method A bisection with inverse quadratic interpolation was used for the algorithm implemented into DemProj Barkalov 1984 The approximation for the change parameter p is found by letting H Lf Va and H pee e Va where Hi and H2 are the arguments from the quadratic equation that are used to solve for p the parameter of change over the projection period Then when the original TFR is greater than the projected TFR _Hi V 2 D Het Hi H2 lt 0 3 where D is the difference between the projected TFR and the TFR from the empirical source such as a survey 1 4 A 3 An Application to Bangladesh As an example the model was employed to project two sets of fertility rates from Bangladesh The first set came fr
80. population Total fertility rate ASFR Sex ratio at birth Life expectancy Intemational migration Model Table C Coale Demeny West CDR 8 4 IMR 54 C Coale Demeny North CDR 8 4 IMR 52 C Coale Demeny East CDR 8 4 IMR 67 C Coale Demeny South CDR 8 4 IMR 80 UN General CDR 8 5 IMR 60 C UN Latin America CDR 8 5 IMR 66 C UN Chile CDR 8 5 IMR 76 C UN South Asia CDR 8 5 IMR 76 UN East Asia CDR 8 6 IMR 44 C Custom CDR 8 4 IMR 54 Ok Cancel Source Ready 0 SAMPLE With this dialogue box you can specify which model life table see glossary should be used for this projection Values for both the four Coale Demeny model life table families and five United Nations model families are shown The display also shows the crude death rate and the infant mortality rate that would be calculated in the first year if you chose the corresponding life table Choose the appropriate table by clicking on the name of the table The age specific mortality rates needed by the program will be calculated based on the life expectancy and model life table when you leave the editor Once you have chosen the model life table click on the International migration tab to move to the next editor If you do not wish to consider international migration in this projection you may skip this editor If you want to use a custom life table select Custom from the list then click on the Custom button at
81. s consider the best fit 3 If neither of the first two options is possible a third option is to compare the crude death rate and infant mortality rate that would result from choosing each model life table with the actual estimates of these indicators The table that provides the closest fit may be the most appropriate The DemProj computer program will generate corresponding crude death and infant mortality rates for the first year of the projection automatically as a guide to choosing the best table Modifying the Model Life Tables Every effort has been made to make DemProj as easy to use as possible This ease of use comes at the expense of some flexibility There may be times when it is desirable to determine an age specific schedule of mortality without using these model life tables DemProj does not contain an editor to allow interactive entry of custom tables of age specific mortality and the majority of the data DemProj contains are survival probabilities not mortality rates However DemProj does allow for the use of a custom life table A custom table can be created by editing the custom life table fie In a typical configuration the computer files containing the information on model life tables are contained in the directory C Spectrum DP All model life table files for females have the extension f while all male files have the extension m The Coale Demeny tables are named cdnorth cdsouth cdwes
82. s is scscesesicssedsssesdedssiessedsccessadssiessedsccersedesiensedeateee 75 Vi REFERENCES voces ERSAN 77 VI GLOSSARY OF TERMS 0 ssc ccssisessscscecsceassvesasassnencansizegsvisavancuasceeiaescsvasasendeetetivesesevane 79 VIII ACRONYMS AND ABBREVIATION G cccccccccsssssssssscccccccssssssssssceeeeceeeseeees 85 APPENDIX A THE COALE TRUSSELL RELATIONAL FERTILITY MODE L ccceeeee A 1 A 1 Description of The MOE cc ccccccccccceresccsceawscewtoaesccstoeseccstoawscastoawedestoaweeuseeted A 1 A 2 Employment of the Model in Projections cccccccccccccrererrrrerereeeees A 3 A 3 An Application to Bangladesh ssssssccccccccceessssssscecccceceeeeeeseeees A S l List of Figures Figure 1 Shift in Fertility Distributions Bangladesh 1975 to 1993 94 eccccccccssesscsscescescessesscescessesecseeseeeees 18 Figure 2 Shift in Fertility Distributions TAIWAN 1956 TO 1983 uo eeessessesetseseeseeseeseseeseeseeesecseeseesesecseeseceeseens 18 Figure 3 Fertility Distribution by TFR UN Sub Saharan Africa Pattern wee ec ccsccsceeceeeseeescsecessesseseeseeeees 20 Figure 4 Comparison of Model Fertility Tables at a TFR Of 4 0 eee eeeseesseeseeceeseceeceeeeseesecseceeeeseesecseeeesaes 21 Figure 5 Shift in Fertility Distributions Bangladesh and UN Asia PATTEM eeccsccssesscssceeceseeseeseeeeeees 22 Figure 6 Shift in Fertility Distributions Bangladesh and UN Sub Saharan Africa Pattern ee
83. s possible to interpolate a TFR for each intervening year Spectrum uses a linear form of interpolation so that the difference between each annual value is the same Other nonlinear forms of interpolation also are possible but are not used in Spectrum SO Life expectancy e 0 The average number of years a newborn can expect to live based on the mortality conditions at the time Life table A table of values based on a series of related functions having to do with survivorship over intervals of time Logit A function of the real number x where x must be between 0 and 1 which is defined as logit x Ln x 1 x Mean age of childbearing The average age of mothers at the time of birth Median age The age that divides a population into two numerically equal groups Model Computer system designed to demonstrate the probable effect of two or more variables that might be brought to bear on an outcome Such models can reduce the effort required to manipulate these factors and present the results in an accessible format Model life table A table of values based on a series of related functions having to do with survivorship over intervals of time Module Synonym for model Net migration The number of people who move to an area minus those who move away Net reproduction rate NRR The average number of daughters that would be born to a woman or a group of women during her lifetime if she passed through al
84. t and cdeast The United Nations tables are named unchile Unea ungen unla and unsa The custom tables are named custom f and custom m These files can be edited with any editor or word processor that can produce ASCIl or text files to enter the desired patterns The format of the model life table files is as follows Row 1 life expectancy at birth Row 2 one year survival ratios for newborns Row 3 one year survival ratios for ages one to two a 33 Rows 4 5 6 one year survival ratios for ages two to three three to four and four to five Row 7 the proportion of births during a five year period that will survive within the 0 4 age group to the end of the period Row 8 the proportion of those aged 0 4 who will survive into the 5 9 age group five years later Rows 9 23 the proportion of the age group 5 9 10 14 79 80 that will survive into the next age group five years later Row 24 the proportion of the age group 80 that will survive five years later Row 25 the infant mortality rate Row 26 the child mortality rate 1 4 In each row the values in the columns correspond to the life expectancy shown in the first row Any of the figures in these files including life expectancy may be changed to produce a new life table To produce an entire schedule of age specific mortality rates for a particular projection enter the life expectan
85. the Centre for Development and Population Activities CEDPA Each manual begins with a discussion of what the model does and why someone would want to use it The manual also explains the data decisions and assumptions needed before the model can be run and possible sources for the data It defines the data inputs and outputs The manual contains a tutorial information on the methodology behind the model a glossary and a bibliography Information about the POLICY Project The POLICY Project is a USAID funded activity designed to create a supportive environment for family planning and reproductive health programs through the promotion of a participatory process and population policies that respond to client needs To achieve its purpose the project addresses the full range of policies that support the expansion of family planning and other reproductive health services including national policies as expressed in laws and in official statements and documents operational policies that govern the provision of services policies affecting gender roles and the status of women and policies in related sectors such as health education and the environment that affect populations More information about the Spectrum System of Policy Models and the POLICY Project are available from Director POLICY Project Futures Group One Thomas Circle NW Suite 200 Washington DC 20005 U S A Telephone 202 775 9680 Fax
86. the goal Sometimes goals are expressed in terms of crude death rates or population growth rates instead of life expectancy In these cases different life expectancy assumptions may be tried to discover a projection that is consistent with the national goals for these other indicators 3 United Nations and U S Census Bureau projections The population projections prepared by the United Nations Population Division and reported in World Population Prospects include assumptions about levels of life expectancy for each country reported These assumptions may be used The U S Census Bureau projections also contain a set of life expectancy assumptions 4 Recent trends and international experience If information is available on life expectancy for several years it may be useful to analyze the trends and develop a future assumption based on continuing past trends It should be noted however that past trends cannot be expected to continue for very long into the future Life expectancy rarely increases at a constant pace throughout an entire demographic transition Rates of decline are often slow at first increase during the middle of the transition and slow again as they approach high levels 5 United Nations model schedule In preparing its population projections every two years the United Nations Population Division uses a model schedule of changes in life expectancy This schedule assumes that life expectancy at birth for both males
87. ti 0 0060 P a 2 a3 0 0050 Pa 2 0 0280 P a 1 0 2460 Pa 0 0280 a 0 0050 a 2 a4 0 0060 pa 2 0 0400 p a 1 0 2200 Pa 0 01609 ati 0 0020 P a 2 aS 0 0027 pa 2 0 0284 a1 0 1570 Pa 0 0804 p ati 0 0117 p a 2 where al a2 a3 a4 and a5 are the first second third fourth and fifth ages in the particular age group and pazis the population of the age group two groups younger than the reference group Pais the population of the age group one group younger than the reference group and so on The 75 79 age group is split with the formulas a75 0 0015 Ps60 64 0 0084 65 69 0 0822 65 69 0 1468 P55 69 0 0191 Pso0 a76 0 0038 40 64 0 0072 165 69 0 0172 De5 69 0 1992 065 69 0 0198 Dso a77 0 0028 P60 64 0 0112 e 65 69 0 0248 65 69 0 2272 D65 69 0 0108 Ps0 a78 0 0013 P60 64 0 0028 165 69 0 0402 65 69 0 2268 65 69 0 0093 Da0 a79 0 0068 Pso 64 0 0128 65 69 0 0344 045 69 0 2000 D65 69 0 0404 Dg0 Ages 80 and above are aggregated and by definition are not split into single years B Survival Ratios Survival ratios are the proportion of the population of a particular age that survives to the next age in the next year The life tables used in DemProj provide single year survival ratios from birth to age one age one to two two to three three to four and four to five Beyond age five the t
88. tion whose various demographic experiences such s2 as mortality chances are consolidated into summary indicators as if to a true birth cohort Total fertility rate TFR The average number of children that would be born alive to a woman or a group of women during her lifetime if she were to pass through all her childbearing years conforming to the age specific fertility rates of a given year Under five mortality rate U5MR The number of deaths to children under the age of five per 1 000 live births United Nations model fertility schedules Five regional schedules prescribed by total fertility rate United Nations model life tables for developing countries A set of families of life table schedules derived from empirical life tables from developing countries based on data from the second half of the 20 century Vital statistics Statistics on demographic events births deaths marriages and divorces which are recorded through an event registration system VI i e Acronyms and Abbreviations AIDS acquired immune deficiency syndrome AIM AIDS Impact Model ASFR age specific fertility rate CBR crude birth rate CDC U S Centers for Disease Control and Prevention CDR crude death rate CPS Contraceptive Prevalence Surveys DHS Demographic and Health Surveys e 0 life expectancy GDP gross domestic product GNP gross national product GR annual growth rate GRR gross reproduction rate HIV human immunodefici
89. to 1983 percent distribution 0 k 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group 1956 1983 Table 3 UN Model Tables of the Age Distribution of Fertility TFR 15 19 20 24 25 29 30 34 35 39 40 44 45 49 Total Sub Saharan Africa 8 2 35 4 29 9 17 4 7 2 1 7 0 1 100 14 0 31 1 24 7 16 6 9 2 3 6 0 6 100 14 9 25 9 22 1 17 1 11 7 6 4 1 8 100 16 1 25 4 22 0 17 0 11 6 6 2 1 6 100 16 4 24 7 22 1 17 3 11 7 6 2 1 5 100 14 7 23 5 21 9 17 9 12 8 V2 2 0 100 Arab Countries 2 7 2 31 1 30 3 19 7 9 0 2 4 0 2 100 3 6 6 29 1 29 8 20 7 10 4 3 2 0 2 100 4 7 6 24 4 26 0 21 1 14 2 6 9 1 4 100 5 8 5 23 1 24 9 21 0 14 2 6 9 1 4 100 6 7 DAA URN 8 8 21 9 24 3 21 1 14 8 7 5 1 6 100 7 8 21 7 25 1 21 9 15 0 7 2 1 4 100 2 2 8 31 1 38 4 21 1 5 9 0 7 0 0 100 3 2 4 23 5 33 7 25 6 11 9 2 8 0 1 100 4 3 8 20 8 27 9 24 6 15 7 6 3 0 8 100 5 5 6 21 4 26 6 23 3 15 4 6 7 1 0 100 6 7 9 22 8 26 2 22 0 14 2 6 1 0 9 100 7 11 8 24 1 24 1 19 5 13 0 6 3 1 3 100 2 6 1 32 5 32 9 19 4 74 1 6 0 1 100 3 7 7 27 9 29 4 21 0 10 5 3 2 0 3 100 4 8 8 23 7 25 3 20 9 13 9 6 5 1 3 100 5 10 1 23 3 24 5 20 4 13 7 6 6 1 3 100 6 11 0 23 1 24 2 20 1 13 6 6 6 1 3 100 7 11 4 23 1 23 7 19 8 13 6 6 9 1 6 100 Source World Population Prospects as assessed in 1973 Regionality and Model Fertility Patterns the United Nations Model Schedules Aspects of fertility that can vary from one locale to another incl
90. tor like the one shown below Spectrum lej xj Fie Edit Display Options Window Help Demographic data SAMPLE Edit Life expectancy Model life table International migration First year population Total fertility rate ASFR Sex ratio at birth First year population Thousands e 0 4 Ready 0 SAMPLE For each of the inputs required for the population projection there is a tab near the top of the screen 1 To enter data for any of these assumptions click on the appropriate tab to display the editor for that variable 2 Then click anywhere inside the editor to make it active To enter data for any of these assumptions click on the appropriate tab to display the editor for that variable Then click anywhere inside the editor to make it active Although you can enter the data in any order it is generally best to begin by entering the data on the first year population as this information is needed to calculate some of the indicators displayed in the ASFR and Model life table editors Each of the editors is explained in the following pages 3 About the Editors Each editor in DemProj is similar At the very top of the screen the variable name appears At the bottom of the screen are the special edit keys Duplicate allows you to copy information from one cell column or row to another Interoolate to enter a beginning and ending number
91. total net migration but they are not disaggregated by sex The second component of the migration assumption is the distribution of migrants by age for each sex This information also needs to come from national studies There are no simple model tables for patterns of migration by age however the United Nations has devised an approach to developing age and sex migration patterns This approach is based on model schedules of gross migration developed by Castro and Rogers described in United Nations 1989 pp 65 69 Net international migration is not a major component of population change in most countries Often migration can be ignored without a significant effect on the population projection However for special areas such as cities and for some countries migration can be very important Moreover age and sex patterns of migration vary considerably In Nairobi for example migrants to the city consist largely of young males seeking work In other cities such as Kinshasa migrants to the city are composed primarily of entire families In Jordan there was a significant outflow of migrants during the oil boom in the Persian Gulf states of the 1970s and 1980s but during the 1990s there was a net inflow of migrants as families returned to Jordan due to reduced employment opportunities in the Gulf E Current Population Urban and Rural DemProj can be used to make urban and rural population projections along with the national pro
92. u s World Population Data Sheet or the World Bank s World Development Indicators list the total population of most countries of the world but do not provide age and sex specific numbers Population estimates may also be accessed from various Internet sites including the United Nations population projections at http un org esa population unpop htm e the U S Census Bureau site at http www census gov ipc www the Population Reference Bureau site at http www prb org B Fertility A population projection requires information about the level of fertility obtained through the TFR and about its shape obtained through the age distribution 1 The Total Fertility Rate Base Year Estimates The TFR is the number of live births a woman would have if she survived to age 50 and had children according to the prevailing pattern of childbearing at each age group It is not an average of the number of live births for currently living women Rather it is a synthetic measure that expresses the current level of fertility in terms of the average number of live births that would occur per woman if the current age specific fertility rates remained constant and alll women survived to age 50 Estimates of the TFR are available from a number of sources The best sources will be national fertility surveys which have been conducted by most countries A large number have been conducted under a series of international projects
93. uce a single year projection A Calculating the Base Population by Single Ages The first step is to separate the population by five year age groups into single years of age This is achieved through the use of the Beers formulas Beers 1945 The 0 4 age group is split using the following formulas a0 0 3333 p1 0 1636 p2 0 0210 p3 0 0796 p4 0 0283 p5 al 0 2595ep1 0 0780 p2 0 0130 p3 0 0100 p4 0 0045 p5 a2 0 1924 p1 0 0064 p2 0 0184 p3 0 0256 p4 0 0084 p5 a3 0 1329 p1 0 0844 p2 0 0054 p3 0 0356 p4 0 0129 p5 a4 0 0819 p1 0 1508 p2 0 0158 p3 0 0284 p4 0 0115 p5 where pl p2 p3 p4 and pS are the population aged 0 4 5 9 10 14 15 19 and 20 24 respectively and a0 al a2 a3 and a4 are the populations at single ages 0 1 2 3 and 4 respectively Similarly the 5 9 age group is split using the following formulas a5 0 0404 p1 0 2000 p2 0 0344 p3 0 0128 p4 0 0068 p5 a 0 0093 p1 0 2268 p2 0 0402 p3 0 0028 p4 0 0013 p5 a7 0 0108 p1 0 2272 p2 0 0248 1p3 0 0112 p4 0 0028 p5 a8 0 0198 p1 0 1992 p2 0 017213 0 0072 p4 0 0038 p5 a9 0 0191 p1 0 1468 p2 0 0822 p3 0 0084 p4 0 0015 p5 nn The age groups from 10 14 to 70 74 are split using the following formulas al 0 0117 pa 2 0 0804 pa 1 0 1570 Pa 0 0284 Pa 0 0027 P a 2 a2 0 0020 Pa 2 0 0160 p a 1 0 2200 Pa 0 0400 Pp a
94. ude how concentrated the fertility rates are how fast this concentration occurs and how young a shift is displayed The United Nations Population Division has developed regional patterns to describe the shift in childbearing as fertility changes using patterns labeled as sub Saharan Africa Arab nations and Asia In Table 3 the fertility distributions by various total fertility rates are given for each of the four patterns Figure 3 depicts the shifting fertility distribution for the sub Saharan Africa model for changing fertility levels It shows a relatively flat distribution of fertility across ages for high level of TFR and an increasingly peaked distribution reaching a maximum in the age group 2024 when TFR is 2 or 3 Figure 3 Fertility Distribution by TFR UN Sub Saharan Africa Pattern percent distribution 0 35 30 25 20 15 10 5 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age gr Africa TFR 2 Africa TFR 3 x Africa TFR 4 ae A d n O A d at The differences among the model fertility tables can be seen in Figure 4 In this figure the age pattern of fertility is compared for all four tables at a TFR of four The model table for sub Saharan Africa has a higher proportion of fertility concentrated in the youngest age groups while the Asia table has the oldest pattern Figure 4 Comparison of Model Fertility Tables at a TFR of 4 0 perce
95. utions Bangladesh and UN Sub Saharan Africa Pattern percent distribution 35 Bos iq 20 15 10 5 SS 0 15 19 20 24 25 29 30 34 35 39 40 44 45 49 age group BDHS 93 AFRICA TFR 3 AFRICA TFR 5 AFRICA TFR 7 In sum DemProj users should not assume that because their country lies geographically within Asia or sub Saharan Africa or is an Arab country they should necessarily choose that respective region Users should first check their country or region s initial fertility distribution against those given in Table 3 If these shapes do not fit or the country lies outside of those three regions the Average pattern is recommended Combining Data from Fertility Surveys with Model Tables The most common situation is one where data on the distribution of fertility by age are available for the base year However most projections include changing TFR in future years The model tables are useful for estimating how the fertility pattern will change as fertility changes This raises the problem of how to use the base year survey data but still take advantage of the model tables for future values of TFR The simplest solution is to use the fertility survey data for the base year and the model table values for the final year of the projection or the year in which fertility stops changing Interpolating between these two points will yield a fertility distr
96. wauagasheseacabheawagaubaevagadicawadevs 5 F Why Make Population Projections sssssssssssssssssssssssssssssssssssssssees 6 ll STEPS IN MAKING A POPULATION PROJECTION ccccccccccccsesscscecceceeceeeeeeees 7 Ill DEMOGRAPHIC INPUTS AND OUTPUTG ccccccccccccscccscscccccccccceccccceeseeseeeeeeeees 9 A Base Year POPUIGTION a cz siicnsatcyasanesancvanonaccheeanavansnasanaeeayadehevahavabaxaneuedanenanenads 10 B FEY eee er Beare eC e Re ren eee Ree ee oP Ree mnn Nie oR eRET MRERER ES ED ETER E Er rn 12 1 The Total Fertility RM Cs ios code vecaad sess cetecevsten dee slessnseen vedeeSause tanec dedincee soviebentsads 12 Base Year Esti ie eit sits sie cia casiencgste tel oh tine anes ste cab lahat at haste Gants daca tiannainl ats 12 FUTUR ASSUIIO HONS 4 5 coevearacscfeus a a aa a a aa cuca be 13 2 The Age Distribution Of Fertility lt sccccsnseccdeevscesacastecsveseccbavestvcesecessvodeweseces 16 Use of Fertility Models in Population Projections ese ssssssessesesseseseesesssesesseseseee 16 A VATNE EAER ARNAR E E EA AEA AE 17 Regionality and Model Fertility Patterns the United Nations Model Sehed CEE n Teen AEE a RCT ENTER CO TPE NE TC HEBER TON FEN TEE SPE Yen TP 20 Combining Data from Fertility Surveys with Model TADIES ccecesseseeseseeseeeesees 23 The Coale Trussell Fertility Model ssssssesessresssesrssessresresrstsrssrssrssrscsssesresresersee 23 C SINNOTT GUN oeenn neern eee e E
97. xceeding 1 are quite normal see Coale and Trussell 1978 In addition the parameter M partially reflects the average impact of marriage union interruption Gx is the model proportion who ever married Oo Gx is formalized based on a standard density function which in turn takes two parameters the singulate mean age at marriage SMAM which is the arithmetic mean age at first marriage and the initial nuptial age ao which is the age at which a significant number of sexual unions start The value of ao has a narrow range of reasonable variation Usually it runs from 12 some south Asian and Latin American countries to 17 some European countries A 2 Employment of the Model in Projections The Coale Trussell model is simplified in DemProj when used in the projection of fertility schedules It is assumed that in a projection period the fertility change which occurs would affect primarily the stopping patterns or for higher order births the birth soacing pattern And it assumes that the marriage pattern and the pattern of spacing for lower order births would not be altered Thus the model would demonstrate a relationship between the projected age specific fertility rates fa and the probably empirical reference fertility rates foa as f heele Here Va is the Coale Trussell standard age specific schedule of fertility control values given in Table A 1 and p is the parameter of change in the projection
98. xcludes the impact of AIDS This could be done by removing AIDS deaths from the schedule of deaths by age and recalculating life expectancy However AIDS deaths are usually greatly underreported making this approach questionable An alternative approach is to start with an estimate of life expectancy for some year before a significant number of AIDS deaths occurred Then estimate how life expectancy would have changed from that year forward to the base year of the projection in the absence of AIDS This could be done by extrapolating the historical trend or by using the United Nations model schedule shown in Table 4 Life expectancy in the absence of AIDS can be projected into the future in a similar manner It should be noted that the life expectancy assumptions reported in World Population Prospects and World Population Profiles include the effect of AIDS In countries where AIDS is a serious problem these life expectancy projections cannot be used to create a population projection in the absence of AIDS Both organizations do produce special tables that show the non AIDS life expectancy assumptions that can be used in DemProj 3 Age Specific Mortality Model Mortality Tables The mortality inout to DemProj life expectancy at birth indicates overall mortality in a population But Demproj also needs the pattern of mortality in order to produce mortality rates by age group Specifically the rates required by DemProj are survival ratios
99. xt or data in a standardized character format which is transportable between software applications and operating systems Births The total number of annual births Child woman ratio The number of children under the age of five per woman of childbearing age 15 49 Coale Demeny model life tables Families of life tables derived from empirical life tables of Europe and other industrialized nations of the world They are based primarily on data from the first half of the 20 century Coale Trussell relational fertility model This model incorporates 1 the timing of marriage 2 a population s natural fertility and 3 the degree of fertility regulation in a population It permits users to generate a fertility schedule from an empirical baseline and a specific total fertility rate Cohort A group of persons who experience certain events within a specified period of time such as those who are born or who are married in the same year Cohort component projection A projection made by subjecting all cohorts on an annual or five year basis to mortality and migration assumptions and applying fertility assumptions to women of reproductive age nn Crude birth rate CBR The number of live births per 1 000 population in a given year Crude death rate CDR The number of deaths per 1 000 population in a given year Deaths The total number of annual deaths Dependency ratio The ratio of the economically dependent part o
100. y Users can change these parameters by selecting Edit from the menu bar and then Projection The other items in the dialogue box are as follows Currency Name Type in the name to label the currency units Urban rural projection Use these buttons to indicate whether you want to include urban and rural projections as part of your overall projection The default is Do not include urban rural projections Scale Scale refers to the scale used when base year population figures are entered Consider the case when the population in the base year is 10 million If you select a scale of Units then you should enter the base year population as 10000000 If you select a scale of Thousands then you should enter the base year population as 10000 If you select a scale of Millions then you should enter it as 10 For most country applications Thousands will be the best choice It will keep users from having to enter very long numbers while still leaving enough digits for adequate precision 44 re Once all the information has been entered click on the Ok button to close the dialogue box 2 Entering the Base Year Data and Projection Assumptions To enter the base year data and projection assumptions 1 Choose Edit from the menu bar Choose Demography from the pull down menu Choose Demographic data from the Demographic data dialogue box This step will display an edi
101. you have more than one projection loaded alll projections will be displayed in the graphs and tables The number of projections you can load at any one time is determined by the amount of available memory in your computer When you have more than one projection loaded you will be asked to choose a projection when performing certain tasks such as editing assumptions The program will display a list of the projection names and you may choose the appropriate one from the list I Closing a Projection To close a projection that has already been opened 1 Choose File from the menu bar and 2 Close projection from the pull down menu If you have more than one projection loaded you will be asked to select which projection should be closed Closing a projection just removes it from the computer s memory it does not erase it from the hard disk You can open that projection again at any time J Using DemProj Projections with the Excel Version of RAPID Population projections made with DemProj can be used in conjunction with a number of other modules that are part of the Spectrum system They can also be transferred to the special spreadsheet version of the RAPID programs See the RAPID manual for more details on these programs To save a DemProj file in a form suitable for use with the Excel versions of RAPID l ga es Select File from the menu bar Select Export from the pull down menu Select D

DemProj Manual - Johns Hopkins Bloomberg School of Public Health

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