following lives from birth and through the adult years Jenny Neuburger GeNet meeting, 26 September 2008 Trends in the Relative Pay of Women and Men Across Three British Birth Cohorts

following lives from birth and through the adult years Research questions How has womens average pay changed relative to mens since 1970? How does womens average pay change with age, relative to mens? What difference does it make adjusting for changes in women's employment participation?

Censuses (1951, 1961, 1966) Labour Force Survey, Increases in womens paid employment

New Earnings Survey , ASHE Improvement in (employed) womens relative pay

British Birth Cohort Studies National Survey of Health and Development (NSHD) - All babies born in England, Scotland and Wales in one week of March Follow-up survey 5,362 in Stratified sample. - Surveyed 22 times, most recently in 2006 (age 60). National Child Development Study (NCDS) - All (17,634) babies born across Britain in a week of March Seven follow-up studies. Added Non British-born children at ages seven and eleven. - 11,419 interviewed in 2000 (age 42). British Cohort Study (BCS) - All (17,287) babies born across Britain in a week of April Seven follow-up studies. Non British-born added at ages five, ten and sixteen. - Non-response problems. 9,665 interviewed in 2004 (age 34).

% of women in paid employment, by age & cohort

following lives from birth and through the adult years Ratio of womens to mens mean hourly pay, by cohort & age

Truncated distribution of wage offers In paid work Not in paid work Wage offer Mean wage Mean wage offer

Imputation characteristics Childhood Fathers occupation at two ages Mothers age when cohort member born Parents education Scores in maths and reading tests at age 10 or 11 Number of siblings Number of older siblings Adulthood Highest qualifications Occupational status of first job Years in full-time and part-time employment Any children, children under five, more than one child Lives in London or the South East

Results I: Who is in employment? Women with higher education and ability more likely to be in paid work (and to work full-time) Differences reduce with age. Non-employees more heterogeneous group at older ages.

Results II: What do imputed wage distributions look like? Imputed mean wage is lower than mean wage for women in six out of the seven surveys (between two and eight per cent lower) Full-time mean is much lower for women (up to 15 per cent) when part-timers and non-employees assigned full-time wage Mean is lower for men at two ages; 33 (1991) and 42 (2000) for NCDS

following lives from birth and through the adult years Imputed and actual log wage distributions, NSHD NSHD women age 26NSHD women age 31

Results III: Trends in actual and potential pay ratios

following lives from birth and through the adult years Conclusions Womens average actual and potential pay has increased relative to mens across cohorts, but decreases with age We underestimate cross-cohort improvements in young womens potential pay if we ignore selection into employment Gender pay gaps for full-time workers understate gender inequality in full-time pay opportunities

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following lives from birth and through the adult years Sample sizes NSHD 26 (1972) NSHD 31 (1977) NCDS 23 (1981) NCDS 33 (1991) NCDS 42 (2000) BCS 30 (2000) BCS 34 (2004) Employed Observed wage Wage missing Missing covariates(255)(267)(1640)(1573)(1764)(1364)(1106) Not employed Imputed Not imputed Missing covariates(322)(284)(1074)(993)(776)(713)(586) Total in survey

following lives from birth and through the adult years % of women with children, by qual, age and cohort

following lives from birth and through the adult years % of women with children, by qual, age and cohort

following lives from birth and through the adult years % mums employed when child < 5 yrs, by qual & cohort

following lives from birth and through the adult years Nearest-neighbour matching based on propensity score Prob(work) = 1 Prob(work) = 0 Not in paid work In paid work Propensity score

following lives from birth and through the adult years Imputed potential and actual mean wages NSHD 26 (1972) NSHD 31 (1977) NCDS 23 (1981) NCDS 33 (1991) NCDS 42 (2000) BCS 30 (2000) BCS 34 (2004) Women Imputed mean 1.28 (0.02) 1.40 (0.01) 1.49 (0.01) 1.77 (0.01) 1.90 (0.01) 1.92 (0.01) 2.09 (0.01) Mean wage 1.40 (0.01) 1.43 (0.01) 1.52 (0.01) 1.83 (0.01) 1.91 (0.01) 1.96 (0.01) 2.13 (0.01) Employees Imputed sample Men Imputed mean 1.78 (0.01) 1.87 (0.01) 1.68 (0.01) 2.19 (0.01) 2.35 (0.01) 2.15 (0.01) 2.36 (0.01) Mean wage 1.78 (0.01) 1.87 (0.01) 1.68 (0.01) 2.20 (0.01) 2.36 (0.01) 2.16 (0.01) 2.37 (0.01) Employees Imputed sample