1. World Population Prospects The 2010 Revision Gerhard K. Heilig United Nations, Department of Economic and Social Affairs (DESA) Population Division - Population Estimates and Projections Section www.unpopulation.org 5 May 2011

2. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York WPP preparation process: Overview Estimation of population, fertility, mortality and migration Probabilistic projection of total fertility Projection of life expectancy Projection of migration Table of content 1 2 3 0 4

3. United Nations Department of Economic and Social Affairs – Population Division Team Chief Gerhard K. Heilig Population Affairs Officer Danan Gu Population Affairs Officer Nan Li Population Affairs Officer Thomas Spoorenberg Population Affairs Officer Kirill Andreev Population Affairs Officer Patrick Gerland Editorial Assistant Neena Koshy Information Systems Assistant Sarada Ravinuthala Information Systems Assistant Chandrasekhar Yamarthy

4. United Nations Department of Economic and Social Affairs – Population Division Mandate Prepare the World Population Prospects  Official United Nations population projections, used throughout the UN System  Recent revisions prepared every second year  Latest revision: 2010 (230 countries)  22 revisions since the early 1950s Prepare the World Urbanization Prospects  Estimates and projections of urban population for 230 countries  Estimates and projections of major urban agglomerations (about 5000)  Latest revision: 2009  Since 1988 Publish results, develop methodology  Web sites, wall charts, CD-ROMs/DVDs, databases  Model life tables, probabilistic projections (Bayesian Hierarchical Model) Develop specialized databases and software  DemoBase, DemoData, DataArchive  Estimation and projection software, probabilistic models, data checking

5. United Nations Department of Economic and Social Affairs – Population Division 1 World Population Prospects: What we do 60% of Workload Update and development of new databases and software, server and database maintenance, backup Start of WPP Evaluation Adjustments Data Collection 230 countries / areas Uploading to Database Calculation of Variants Aggregation of Regions Epidem. Modeling for AIDS Countries 3 CD-ROMs / DVDs Online Database Web Sites Statistical Reports Vol. 1, 2 Early Release Data Wall Chart 25% of Workload 15% of Workload Checking of Results 2 Methodological Report (on web site) Start of WUP Fixing of Errors Data Collection, Estimation Projection, Aggregation, Checking Output Production 0 Consulting / Feedback Responding to clients

6. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 0 1.Census data + post-enumeration surveys (from United Nations Demographic Yearbook database and directly from National Statistical Offices) 2.All available demographic and health surveys (DHS, DSS, MICS, WHS, etc.) for estimating fertility and mortality 3.Estimates from population and vital registers (from statistical reports of National Statistical Offices or their web sites) 4.Scientific reports and data collections (Human Mortality Database, child mortality estimates, etc.) 5.Data and estimates provided by other international agencies (CELADE, Regional Commissions, EUROSTAT, ESCAP, UNICEF, UNAIDS, WHO) WPP data sources

7. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Methodology The UN approach to estimating population (by age and sex), fertility, mortality and migration Availability & Data Quality 1

8. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Register Data: Population by Age and Sex Sufficient for cohort-component projection Partially sufficient for cohort-component projection Not sufficient for projection ≈ 2/3 of countries have insufficient population estimates by age and sex to establish consistent time-series from 1950 to present 1

9. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Data Sources: Child Mortality Estimation (WPP2008) 1 Number of countries according to the most recent data available Only countries with a population of 100,000 or more in 2009

10. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Data Sources: Adult Mortality Estimation (WPP2008) 1 Number of countries according to the most recent data available Only countries with a population of 100,000 or more in 2009

11. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Data Sources: Fertility Estimation (WPP2008) 1 Number of countries according to the most recent data available Only countries with a population of 100,000 or more in 2009

12. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Population from Censuses 1

13. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Population from Censuses 1 Under-reported migrant workers Under-reported births

14. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Total Population 1

15. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Total Population 1

16. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Total Population 1

17. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Mortality: 1q0, 5q0 (Senegal) 1

18. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Mortality: 5q0 (Senegal) 1

19. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Mortality: 45q15 (Senegal) 1

20. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Fertility: TFR (Senegal) 1

21. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Fertility: ASFR (Bangladesh) 1

22. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Estimation of Fertility: ASFR (Bangladesh) Lines are weighted cubic spline and loess regression trends 1

23. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Data Quality Assessment (based on WPP2006) 1

24. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Methodology: The UN approach to projecting total fertility A Bayesian Hierarchical Model (BHM) based on bi-logistic decline curves of fertility 2

25. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Model of fertility decline Model: Bi-logistic function to estimate the rate of fertility decline 2

26. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Projections: Fertility A. From high to low fertility B. From medium to 1.85 2

27. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Model of fertility decline Model: Bi-logistic function to estimate the rate of fertility decline In probabilistic fertility projection: Parameters values are replaced by distributions. Some 100,000 trajectories of fertility decline are calculated by sampling from these parameter distributions. 2

28. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Fertility models and empirical data 2

29. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York BHM: A fertility transition model Phase I: Not modeled. Phase II: Fertility transition, modeled by Bayesian Hierarchical Model (BHM) Phase III: Modeled with a first order autoregressive time series model [AR1], with its mean fixed at the approximate replacement-level fertility of 2.1 2

30. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 2 BHM: A fertility transition model

31. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 2 BHM: A fertility transition model

32. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 2 BHM: Bi-logistic functions and TF projections

33. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 2 Probabilistic Projection of Population Based on estimates from WPP2010; probabilistic fertility, deterministic mortality

34. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 2 Probabilistic Projection of Population Based on estimates from WPP2010; probabilistic fertility, deterministic mortality Total Population Population age 15-64

35. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York 2 Probabilistic Projection of Population Based on estimates from WPP2010; probabilistic fertility, deterministic mortality Total Population Population age 15-64

36. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Methodology: The UN approach to projecting life expectancy 3

37. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Models for projecting life expectancy at birth Illustration of the double-logistic function (based on a curve from Japan). The left plot illustrates the double-logistic function of 5-year gains in life expectancy. The right plot is a time-series of life expectancy, e(0), with gains modeled according to the double-logistic function 3

38. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Models for projecting life expectancy at birth 3 Illustration of the double-logistic function (based on a curve from Japan). The left plot illustrates the double-logistic function of 5-year gains in life expectancy. The right plot is a time-series of life expectancy, e(0), with gains modeled according to the double-logistic function

39. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Models for projecting life expectancy at birth 3

40. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Models for projecting life expectancy at birth 3

41. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Projections: Mortality models and empirical data 3

42. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Probabilistic mortality projection Data: Male life expectancy at birth from 1950 through 2005; Estimates from UN World Population Prospects (WPP2006) 3

43. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Data Checking 5

44. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York DemoData: Empirical Database 5 Different Data Sources

45. United Nations Department of Economic and Social Affairs – Population Division Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects, the 2010 Revision. New York Thank You ! www.unpopulation.org