International Workshop on Population Projections using Census Data

1. International Workshop onPopulation Projectionsusing Census Data 14 – 16 January 2013 Beijing, China

2. Session IV:Projecting the levels of mortality, fertility, and migration • Projecting life expectancy at birth • Projecting total fertility • Projecting international net-migration http://unstats.un.org/unsd/demographic/meetings/wshops/China2013/list_of_docs.htm

3. Projecting levels of mortality Overview

4. Projecting levels of mortality • Mortality change (and fertility change) are processes where new behavior is gradually being adopted by people. It is similar to the processes of a new product penetrating a market. In other words: A diffusion process. • Diffusion processes are often modeled by a logistic function.

5. Projecting levels of mortality • Mortality change (and fertility change) are processes where new behavior is gradually being adopted by people. It is similar to the processes of a new product penetrating a market. In other words: A diffusion process. • Diffusion processes are often modeled by a logistic function.

6. Projecting levels of mortality

7. Projecting levels of mortality Δt=100 K=90

8. Projecting levels of mortality I: United Nations Model

9. Projecting levels of mortality I: United Nations Model

10. Projecting levels of mortality I: United Nations Model

11. Projecting levels of mortality I: United Nations Model

12. UNPD_MorModel.xlsm 1. Enter description 2. Enter your data 2. Select a model for each sex

13. UNPD_MorModel.xlsm

14. UNPD_MorModel.xlsm

15. Projecting level of mortality II:US Census Bureau Model • The model in spreadsheet E0LGST.xls interpolates and extrapolates life expectancies at birth, by sex. The program fits a logistic function to 2 to 17 life expectancies at birth, given the upper and lower asymptotes.

16. E0LGST.xls • Input data for E0LGST.xls • Table number [“Table 123”] • Country name and Year [“Poplandia: 1960 and 1980”] • Lower asymptote [leave default] • Upper asymptote [leave default] • 2-17 data points of observed life expectancy • Dates for life expectancy [Decimal years: 1960.5 for midyear] • Values for male, female life expectancy • Sex ratio at birth [male births per female births] • Start year for listing results • Sources of input data

17. E0LGST.xls 1. Enter description 2. Enter observed life expectancies 3. Enter parameter 4. Retrieve projection(Automatic update)

18. E0LGST.xls

19. E0LGST.xls

20. Hands-on exercise: Mortality • Make yourself familiar with the Excel templates • E0LGST.xls [USBC] • UNPD_MorModel.xls/UNPD_MorModel.xlsm [UNPD] • Prepare a projection using a target level of life expectancy or a typical rate of change. • Validity check I: Sex-differentials in e0

21. Hands-on exercise: Mortality • Validity check II: Explore ways to ensure that the projected trends are compatible with past trends.

22. Projecting levels of fertility Overview

23. Projecting levels of fertility I:United Nation Model • Applies a similar model as for mortality. • Not the level itself, but the rates of changes are modeled • Incorporates the observation that during the demographic transition, fertility first changed slowly, then accelerated and finally decelerated

24. UNPD_FerModel.xls 1. Enter description 2. Enter data 3. Select a model

25. UNPD_FerModel.xls

26. Projecting level of fertility II:US Census Bureau Model • The model in spreadsheet TFRLGSTNew.xls interpolates and extrapolates Total Fertility Rates (TFR). The program fits a logistic function to 2 to 17 TFRs, given the upper and lower asymptotes.

27. TFRLGSTNew.xls • Input data for TFRLGSTNew.xls • Table number [“Table 123”] • Country name and Year [“Poplandia: 1960 and 1980”] • Lower asymptote [leave default] • Upper asymptote [leave default] • 2-17 data points of observed TFR • Reference dates for TFR [Decimal years: 1960.5 for midyear] • Values for TFR • Start year for listing results • Sources of input data

28. TFRLGSTNew.xls 1. Enter description 2. Enter observed TFR 3. Enter parameter 4. Retrieve projection(Automatic update)

29. TFRLGST.xls

30. TFRLGSTNew.xls

31. Hands-on exercise: Fertility • Make yourself familiar with the Excel templates • TFRLGST.xls [USBC] • UNPD_FerModel.xls/UNPD_FerModel.xlsm [UNPD] • Prepare a projection using a target level of Total Fertility or a typical rate of change. • Validity check I: Explore ways to ensure that the projected trends are compatible with past trends.

32. Projecting levels of Migration Overview

33. Projecting levels of Migration • International migration is the most challenging part of a population projection exercise: • Reliable data on the number of immigrants and emigrants are often not available • Migration exhibits strong fluctuations that make extrapolations difficult, if not untenable. • Not possible to calculate meaningful demographic rates (exposure/occurrence rates) for immigration and net migration. • International (net) migration is often formulated in terms of absolute numbers. Because if its irregular fluctuations, (net) migration is often kept constant over time.

34. Excursion: Test data • Spectrum comes with a complete database of national estimates and projections for all countries (WPP2010). • The data are formatted into time series for single years, and into single years of age. • How to obtain the data?

35. Spectrum: Step 1

36. Spectrum: Step 2

37. Spectrum: Step 3

38. Spectrum: Step 4

39. Spectrum: Step 5

40. Spectrum: Step 6

41. Spectrum: Step 7.1

42. Spectrum: Step 7.2 Copy to clipboard Paste into Excel Transpose, if necessary