Population censuses and sample surveys as a source

Population censuses and sample surveys as a source of fertility statistics 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Methods used for fertility statistics Reverse survival The own-child Birth history reconstruction Birth histories Fertility statistics Recent births Children ever born 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Reverse survival – the rational o Number of births in the population during the year prior to the census = population under 1 year of age in the census * reverse survival factor o Reverse survival – adjustment for mortality (persons died before the census was taken) o If no complete civil registration data, reverse survival can be used to estimate the following for 15 years prior to census (some surveys): n Number of births n Crude birth rates n General fertility rates o Assumption: No migration! (or can be neglected) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Reverse survival - Information needed o Age – by single years n Better if collected as date of birth o Level of mortality, can be obtained from n Children ever-born and surviving (for estimated life tables) o Total number of persons in a year (for crude birth rate) o Number of reproductive age women (general fertility rate) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Reverse survival - Estimation o Total number of births x years before the census = population x year of age in the census * reverse survival factor 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Reverse survival - tabulation o Population by single years of age 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Reverse survival - quality o The quality of reverse survival estimates of births and birth rates depends on the accuracy of n Age distribution (most important) n Reverse survival factors n Extend of migration (may be important to small areas) o Assessment of quality: compare estimates from different sources at different times 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

The own-children method the rational o Match the children reverse-survived with their mother disaggregate reverse-survived births by age and/or other characteristics of mother o Any person under age 15 child o Note: biological children only 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

The own-children method - information needed o Age, by single years o Is mother of the child alive and living in the same household? o If yes, which person is the mother? n Line number of the mother (for this child) OR n Relation to head of household (applies for nuclear households or similar types) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

The own-children method - tabulation Age of mother Age of child 0 1 … 13 14 15 16 … 63 64 Non-own children 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

The own-children method - estimation o Age specific birth rate 10 -15 years preceding a census or survey 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

The own-children method - quality o The quality of own-children estimates of age-specific fertility rates depends on the accuracy of n The quality of matching! n Age distribution (more important if age exaggeration) n Reverse survival factors n Extend of migration (may be important to small areas) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth history reconstruction – the rational o Own-children methods: n If number of own-children = number of children ever-born birth history n If number of own-children < number of children ever-born some children live elsewhere or died o Birth history reconstruction: n Imputes years of births for surviving children living elsewhere and deceased children 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth history reconstruction - information needed o Age, by single years o Identify mother (line number or relation to the household head) o Number of children ever born o Number of surviving children 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth history reconstruction - Tabulation (age-parity) Year of birth of first child (years prior to census) 55 54 … 2 1 Age of women at end of year of first birth 0 1 … * * 10 * … * * 11 … … … * * 63 * 64 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth history reconstruction - Tabulation (parity-duration) Year of second child (years prior to census) Completed years in parity 1 at end of year of second birth 21 20 … 2 1 * * … * * 0 * … * * 1 … … … * * 19 * 20 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth history reconstruction -estimation o Age-parity-specific birth rates (all women at certain age) o Birth rates specific for parity and duration in parity 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth history reconstruction - quality o Additional quality concerns: n Imputation of dates of birth for non-own and deceased children o If level of mortality is low and most children under age 15 lives in the same household as their mother, the influence of imputation is minimum. 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Children ever born – some background o Widely used for over 50 years (although still a lot of problems) o Important for countries do not have complete birth registration o Also important for countries with complete birth registration n Provide fertility measures on birth order and parity of women n Study fertility by socio-economic characteristics 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Children ever born - information needed o How many children has [this woman] had in her lifetime? n incl. all live births n Could be elaborated into a number of questions o Asked to all women o Sex of the child sex ratio at birth 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Children ever born - tabulation Age of women Number of children ever born 0 1 … 14 15+ CEB not stated Total women Total children born 10 -14 15 -19 … 80 -84 85+ NS Total 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Children ever born - tabulation o A few important issues: n Do not group the numbers of children, except the last open category n Distinguish children ever born not stated from no children 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Children ever born - estimation o o o Parity distribution Parity progression ratios Average number of children ever born Completed fertility Total fertility rates Age-specific birth rates 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Children ever born - quality o Underreporting of children ever born n More serious for older women n Can use certain adjustment to fix o Failure to record childless n Proportion of childless women too low and average number of children born too high. n Still a serious problem in many countries o Selection error n Use women enumerated in census/survey to represent past experience – not a big problem though 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Recent births - information needed 1. Did [this woman] have any live birth during the past 12 months (if multiple, indicate number)? OR 2. What was the year and month of your most recent birth OR 3. Have there been any live births in this household during the last 12 months? 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Recent births - tabulations Question 1 and 3: Age of women Number of births in the last 12 months Question 2: Age of women # of women having birth in Jan 05 Feb 05 … Dec 05 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Recent births - estimation o The questions are subject to underreporting of births – certain adjustment is needed o Age of women during the census to be adjusted to age at giving birth 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Recent births - quality o Reporting errors: n Poor performance of fieldworkers n “reference period error”: uncertain of the date of birth vs the reference period n Reluctant to report o Selection errors: n Excluded women had a birth recently but died before the census n Excluded household had a birth recently but dissolved before the census n Not significant in most cases, however could become an issue when many deaths occurred in a short period (HIV/AIDS) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth histories – some background o An important source on infant and child mortality o Include many questions, limited to 5000 or 10000 women o WFS or DHS o Age-specific birth rates or mortality rates 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth histories – information needed o Birth history of a woman: n All children she has had n Living or deceased? n Characteristics of the children: o Sex o Date of birth o Type of birth (single, twin etc) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Birth histories – quality o Reporting errors 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Conclusion o Methods are available when complete civil registration system does not exist. Civil registration, however, is still the best source. o Can also be used to evaluate the quality of civil registration data o Quality concerns 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

References: n Handbook on the Collection of Fertility and Mortality Data, United Nations (2003) n Manual X Indirect Techniques for Demographic Estimation, United Nations (1983) 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Example – Romania 2002 civil registration 2001 census Age Births female population F Children ever born Total female P P/F 15 -19 28503 795868 0. 06 798298 42648 18. 72 306. 75 20 -24 77518 943208 0. 38 852731 339884 2. 51 6. 67 25 -29 66793 905641 0. 79 829758 802501 1. 03 1. 31 30 -34 36063 963055 1. 06 955730 1367407 0. 70 0. 66 35 -39 8395 613781 1. 19 586945 1102760 0. 53 0. 45 40 -44 2327 768725 1. 22 723378 1522711 0. 48 0. 39 45 -49 139 820343 1. 23 809430 1761109 0. 46 0. 37 Source: United Nations Demographic Yearbook 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Example - Bahrain 2002 civil registration 2001 census Age Births Female Population F Children Ever born Total female P P/F 15 -19 349 25433 0. 01 496 1037 0. 48 47. 51 20 -24 2645 27373 0. 10 8392 9259 0. 91 3. 65 25 -29 4147 27436 0. 15 26150 16925 1. 55 1. 69 30 -34 3413 28453 0. 12 47860 20388 2. 35 1. 45 35 -39 2299 26342 0. 09 67362 21079 3. 20 1. 49 40 -44 655 20474 0. 03 67835 17557 3. 86 1. 58 45 -49 51 13181 0. 00 49733 11645 4. 27 1. 70 Source: United Nations Demographic Yearbook 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007

Example - Kazakhstan 1999 civil registration Age Femal e popul a t i Birth o s n F 1999 census Childr e n ever b o r n 151 2233 70511 9 4 0 P/F 4 33746 37918 6 6 6249 3 0. 6 3 1 1. 31 0. 0 0. 4 P 6775 6 0. 0 5 5 1. 14 202 8099 65362 4 1 2 Total femal e Source: United Nations Demographic Yearbook 25 - 5841 2010 World 56037 Programme on Population and Housing Censuses 2 5687 1. 0 79950 8 1. 3 Workshop Statistics in the UNESCWA Region 9 6 on Civil 6 Registration 5 5 and Vital 2 7 1. 31 Cairo, Egypt, 3 - 6 December 2007 30 - 11203 5587

Data availability - children ever born* Country Egypt Bahrain Iraq Palestine Qatar Yemen Year of data 1986 1991 and 2001 1987 and 1997 1986 1994 Source: United Nations Demographic Yearbook 2010 World Programme on Population and Housing Censuses Workshop on Civil Registration and Vital Statistics in the UNESCWA Region Cairo, Egypt, 3 - 6 December 2007