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Understanding the Effects of Early Motherhood in Britain. Ian Walker (LUMS) and Yu Zhu (Kent) Labour Force Survey User Meeting, 15 December 2009. UK Policy.
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Understanding the Effects of Early Motherhood in Britain Ian Walker (LUMS) and Yu Zhu (Kent) Labour Force Survey User Meeting, 15 December 2009
UK Policy • “Teenage mothers are less likely to finish their education, less likely to find a good job, and more likely to end up both as single parents and bringing up their children in poverty.” Tony Blair, SEU Report, 1999 • “…. promise to halve teenage pregnancy rate by 2000…” Health of the Nation White Paper 1992
“What works” for (US) teen pregnancy ? • Access to family planning service has moderate effects (Levine and Kearney, REStat, 2009) • Welfare doesn’t matter (Kearney, JHR 2002) • School/community programs • Sex education programs with an abstinence focus • ineffective at reducing rates of sexual activity • But no effect on contraceptive use • Sex education with a contraception focus • Moderate increase in contraceptive use among sexually active teens • But no increase in sexual activity • Crying dolls don’t (themselves) have any effect
Teenage conceptionsBirthoutcome by age at conception, England 1997
Cross-country comparisonsLive birth rate to women aged 15–19, latest available figures
European trendsLive birth rate to women 15–19: various EU countries 73–96
English-speaking trendsLive birth rate to women aged 15–19: UK, US, Au, NZ, Canada
Later life outcomesEffects of teenage birth & of clear childhood poverty Source: K Kiernan & J Hobcraft 1999. Analysis of NCDS
Teen mums (A@FB<20) vs rest (BCS70) Education Log wage at 33
Causality? • OLS estimates (and cross-tabs) • Typically indicate large negative socio-economic effects of early motherhood • suggesting interventions aimed at reducing the incidence of teenage births/conceptions. • But is early motherhood • a pathway to future disadvantage ? • or just an indicator of prior disadvantage? • Estimates of the “causal” effect • typically indicate small (often insig) effects • suggesting that the disadvantage already existed • Are there unobserved differences?
Solutions to the causality problem • Family fixed effects (twins, siblings and cousins) • Ribar (JPopEcon, 1999), Rosenzweig and Wolpin (Etrica, 1995), Hoffman, Foster and Furstenberg Jr (Demography, 1993), Geronimus and Korenman (QJE 1992), Bronars and Groggar (AER 1994 ) • IV / Natural experiments • Menarche • Chevalier and Viitinanen (JPopEcon 2003) • Klepinger, Lundberg and Plotnick (JHR 1998) • Miscarriage • Hotz, McElroy and Sanders (REStuds1999) • Kaplan, Goodman and Walker (IFS WP 2004) • Ashcraft and Lang (JHR 2007) • Fletcher and Wolfe (JHR 2009)
Existing results • Most FE work is on US PSID, or NLSYW • Exploits siblings • Datasets are small and unrepresentative • Or twins • Gives the effects of 2 vs 1 not 1 vs 0 • Existing IV work uses • Menarche • Correlated with early-sex but not with early-birth • Probably non-random anyway • Miscarriage • Probably non-random • Results sensitive to including local area FEs • Misreported abortions • Not many teen mums, even fewer teen miscarriages
This paper • Effect of teen-mum on “worklessness” • Major govt objective • Strongly correlated with teen motherhood • Instrumental Variables (IV) • RoSLA: raises oppor-tunity cost of having child when young (e.g. Kruger et al 2009) • Month of birth: within school cohort peer effects
Sample selection • Women aged between 25-35 in England & Wales in LFS 1984-2007, who had first birth by 25 • 80k distinct mothers, of which 28.5% had first birth by the 20th birthday • Multiple treatment groups: motherhood by age 16; and at age 17, 18 and 19, as well as all teen mums (i.e. all ≤ 19). • Same control group: first child at age 20-25
Linear probability model estimates Exogenous teen motherhood on worklessness probability
Month of birth effects on A@FBRatio of Mar-Aug births relative to Sept-Feb births • Crawford et al IFS Commentary 2007 • MoB matters for cognitive outcomes • Relative odds of teen motherhood • Effect stronger at lower ages
Endogenous teen motherhood on worklessness(2nd stage results, first birth by 17)
Endogenous teen motherhood on worklessness(1st stage results and diagnostic test, first birth by 17)
Sensitivity Checks • Very similar results when looking at the effect of first birth before 20 • Size of the teen mum effect virtually zero • Month of birth insignificant in the first stage • Results hold when only using RoSLA or only using month of birth • Results also robust wrt the window of RoSLA (say 5 years before and after the introduction)
Conclusion • Strong negative correlation between teen motherhood and worklessness in the raw data • But no evidence of a causal effect of early motherhood on worklessness later in life • Despite strong IVs • Policymakers need to be aware of unobserved heterogeneity • Teen motherhood doesn’t seem to matter • at least for this outcome
Extensions • Outcomes for the child • Ante-natal care compliance, birth weight (MCS) • Accidents, health (HSE), child well-being (BHPS) • Education, teen-motherhood (BCS, NCDS, LFS) • Outcomes for the mother • Wages, marital status, poverty, welfare ..... (LFS) • Maternal well-being ..... (BHPS) • ECHP, SILC, EU-LFS data, CPS, NSAF, HILDA • Modelling the joint determination of teen-sex and teen-motherhood (HSE) • Does early-sex lead to bad outcomes?