1. A comparison of the characteristics of childless women and mothers in the ONS Longitudinal Study Simon Whitworth Martina Portanti Office for National Statistics

2. Research aim To measure the extent to which women in the LS who remain childless throughout their lifecourse are distinctive from LS members who become mothers.

3. Childlessness Compared to studies of low fertility, childlessness has received less attention within the literature Most studies of childless are based on small scale samples and rely heavily on qualitative methods. This research uses for the first time the ONS Longitudinal Study (LS) to explore lifelong childlessness as a research topic in its own right.

4. Definition ‘The Longitudinal Study is a study containing linked census & vital events data on a 1 per cent sample of the population of England & Wales.’ Information from the 1971, 1981, 1991 & 2001 Censuses has been linked across censuses as well as information on events such as births, deaths & cancer registrations Series LS No. 7, ‘Longitudinal Study 1971-1991 History, organisation & quality of data’, Hattersley L. & Creeser R. 1974- Longitudinal Study was started to improve the analysis of occupational mortality & to provide better information on fertility & birth spacing

5. Structure of the LS 1971 Census 530,000 sample members selected 513,000 traced 1981 Census 536,000 sample members selected 528,000 traced 1991 Census 544,000 sample members selected 535,000 traced 2001 Census 540,000 sample members selected 536,000 traced Linked Events Births to sample women 253,000 Infant deaths 2,000 Widow(er)hoods 80,000 Cancer registrations 110,000 Exits Deaths 233,000 Embarks 39,000 Entrants New Births 264,000 Immigrants 164,000 2011 Census 5??,000 sample members selected 1971 Census 530,000 sample members selected 513,000 traced 1981 Census 536,000 sample members selected 528,000 traced 1991 Census 544,000 sample members selected 535,000 traced 2001 Census 540,000 sample members selected 536,000 traced Linked Events Births to sample women 253,000 Infant deaths 2,000 Widow(er)hoods 80,000 Cancer registrations 110,000 Exits Deaths 233,000 Embarks 39,000 Entrants New Births 264,000 Immigrants 164,000 2011 Census 5??,000 sample members selected 1971 Census 530,000 sample members selected 513,000 traced 1981 Census 536,000 sample members selected 528,000 traced 1991 Census 544,000 sample members selected 535,000 traced 2001 Census 540,000 sample members selected 536,000 traced Linked Events Births to sample women 253,000 Infant deaths 2,000 Widow(er)hoods 80,000 Cancer registrations 110,000 Exits Deaths 233,000 Embarks 39,000 Entrants New Births 264,000 Immigrants 164,000 2011 Census 5??,000 sample members selected 1971 Census 530,000 sample members selected 513,000 traced 1981 Census 536,000 sample members selected 528,000 traced 1991 Census 544,000 sample members selected 535,000 traced 2001 Census 540,000 sample members selected 536,000 traced Linked Events Births to sample women 253,000 Infant deaths 2,000 Widow(er)hoods 80,000 Cancer registrations 110,000 Exits Deaths 233,000 Embarks 39,000 Entrants New Births 264,000 Immigrants 164,000 2011 Census 5??,000 sample members selected

6. Census samples available for analysis 1 census 2 censuses 3 censuses 4 censuses 513,000 19711981 528,000 535,000 19912001 536,000 408,000 420,000 418,000 327,000 331,000 256,000 Total traced LS members: 1,019,000

7. The study cycle of an LS member 1950 1970 1980 2010 1990 2000 2001 Census 1991 Census 1981 Census 1971 Census Born 1955 Entry Birth #2 Birth #1 Events Exit Re-entry Death of spouse Cancer Events Death

8. LS events Births Live & still births (all women in the sample) Cancer registrations Deaths Infant mortality (deaths of infants born to women in the sample) Deaths of sample members' spouses International migration - immigration, emigration & re-entry

9. Census information in the LS Age at Census Sex Marital status Economic activity Occupation Socio-economic group Social class Religion (2001) Self-rated health (2001) Travel to work Provision of unpaid care (2001) Ethnic group (1991 & 2001) National Statistics Socio-economic Classification (2001) Country of birth and, in 1971, parents' countries of birth Limiting, long-term illness (1991 & 2001) Educational qualifications (post-16 qualifications 1971, post-18 qualifications in 1981 & 1991, all qualifications in 2001) Family, household or communal establishment type Housing tenure, number of rooms & amenities Household access to cars & vans Migration in the last year (in 1971, migration five years ago) Area of enumeration (also area of enumeration in 1939) Marriage & fertility history (1971)

10. Why the LS is suitable for this study A cohort of women can be followed through their entire \childbearing age span, thus allowing a study of completed fertility stories. Fertility outcomes can be compared with women's socio- economic characteristics at different times during the life course. These socio-economic characteristics include marital/partnership status, education, economic activity and social class. LS members can be linked to the members of their households at different times, therefore the family context(s) in which specific fertility choices occur can be investigated. The LS has got a larger sample size than other cohort studies, thus allowing more robust statistical inference.

11. Sample selection The analysis focuses on women from the 1956-1960 cohorts, as their entire conventional 15-44 childbearing age span is now covered in the LS. All LS female members born between 1956-1960. We want to ensure that these women are followed up during their entire childbearing age (15-45). -Exclude: immigrants after 15, first embarkations before 45, deaths before 45, those not present at each census. Childless women = those women for whom there was no live or still birth record on the birth records by Dec 2005. Total sample size = 12,578 (2,194 childless and 10,384 with children).

12. Rates of childlessness in LS and England and Wales Birth Cohort% of childless women LSEngland and Wales 195616.516.0 195717.0 195818.0 195917.918.0 196017.818.0

13. Economic activity

14. Social class (2001)

15. Variables entered into the model Limiting long-term illness in 1991 and 2001 Living arrangements in 1981, 1991 and 2001 Economic activity in 1991 and 2001 Social class in 1981, 1991 and 2001 Ethnicity in 2001 Presence of siblings in 1971 Social class of main economic supporter of the household in 1971 Mobility between censuses

16. Women’s model/1

17. Women’s model/2

18. Selected Regression Results Not significant at 0.05: - Social class 1981 -Social class 2001 -Social class of main economic supporter of the household in 1971 - Geographic residence 1971-2001 - Mobility between censuses

19. Partners Various studies have pointed out how contemporary childlessness is occurring more frequently within marriage and cohabitation (Coleman 1996, Hakim, 2005). Investigated the extent to which the partners of childless women were distinctive from the partners of those who had become mothers by 2005.

20. Model with women with a partner in 1991 Variables from the model on the whole sample. Variables added -Marital status of partner -Age of partner -Education of partner -Social class of partner Partners analysis cross-sectional. - Women in a partnership in 1991.

21. Women with a partner model/1

22. Women with a partner model/2

23. Conclusions Using a large scale sample of women this research investigates the degree to which socio- economic characteristics of women, and where present, their partners are related to female lifelong childlessness. Irrespective of their partnership status, women’s own socio-economic characteristics including economic activity and social class are significantly associated with childlessness. Where applicable, partners characteristics including age and marital status, are also linked to women’s childlessness.

24. Conclusions Concentration on identifying and measuring the association between women’s characteristics and childlessness, without debating the direction of this association. Demonstrates the value of using the LS, alongside other established datasources such as the BCS in future studies of childlessness. - The LS is representative of all birth cohorts, thus allowing for more detailed analysis of changes in fertility behaviours over time. - Analysis can be extended to younger cohorts when the data becomes available in the study.

31. Publications Portanti, M and Whitworth, S, 2010, Lifelong childlessness in England and Wales Evidence from the ONS Longitudinal Study, 1, 2, 155-169. Portanti, M and Whitworth, S, 2009, A comparison of the characteristics of childless women and mothers in the ONS Longitudinal Study, Population Trends, 136, 10-20.

32. Acknowledgments Census outputs used here are Crown copyright and are reproduced with permission of the controller of HMSO (LS project 20114, paper’s clearance number 20114E). The authors alone are responsible for the interpretation of the data. The views expressed in this presentation do not necessarily reflect those of ONS.