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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.

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Presentation on theme: "Understanding the Effects of Early Motherhood in Britain Ian Walker (LUMS) and Yu Zhu (Kent) Labour Force Survey User Meeting, 15 December 2009."— Presentation transcript:

1 Understanding the Effects of Early Motherhood in Britain Ian Walker (LUMS) and Yu Zhu (Kent) Labour Force Survey User Meeting, 15 December 2009

2 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

3 What works for (US) teen pregnancy ? Access to family planning service has moderate effects (Levine and Kearney, REStat, 2009) Welfare doesnt 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 dont (themselves) have any effect 3

4 Teenage conceptions Birth outcome by age at conception, England

5 Cross-country comparisons Live birth rate to women aged 15–19, latest available figures 5

6 European trends Live birth rate to women 15–19: various EU countries 73–96 6

7 English-speaking trends Live birth rate to women aged 15–19: UK, US, Au, NZ, Canada 7

8 Later life outcomes Effects of teenage birth & of clear childhood poverty 8 Source: K Kiernan & J Hobcraft Analysis of NCDS

9 Teen mums vs rest (BCS70) EducationLog wage at 33 9

10 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? 10

11 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) 11

12 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 12

13 This paper Effect of teen-mum on worklessness Major govt objective Strongly correlated with teen motherhood Instrumental Variables (IV) RoSLA: r aises oppor- tunity cost of having child when young (e.g. Kruger et al 2009) Month of birth: w ithin school cohort peer effects 13

14 Sample selection Women aged between in England & Wales in LFS , who had first birth by 25 80k distinct mothers, of which 28.5% had first birth by the 20 th 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

15 LFS data 15 Age at 1st birth: All teens20-25 Married Cohabiting Divorced/Sep Single Number of kids Age oldest child Age youngest child % of all 1st births Sample size 2,3994,6097,1208,76922,97957,617

16 Summary Statistics Age at 1 st birth: All teens20-25 Workless (post-) RoSLA Born Mar-Aug Cohort Age Wales (Greater) London Southeast England Rest of England

17 Linear probability model estimates Exogenous teen motherhood on worklessness probability 17 Age at 1 st birth: All teens A): No covariates (0.008) (0.006) (0.005) (0.005) (0.003) B): Cohort effects (0.008) (0.006) (0.005) (0.005) (0.003) C): Cohort effects; age and age squared (0.008) (0.006) (0.005) (0.005) (0.003) D): Cohort effects; age and age squared; year and region dummies (0.008) (0.006) (0.005) (0.005) (0.003) Sample size60,01662,30864,73766,38680,596

18 RoSLA effects on teen motherhood 18

19 Month of birth effects on Ratio of Mar-Aug births relative to Sept-Feb births Crawford et al IFS Commentary 2007IFS Commentary – MoB matters for cognitive outcomes Relative odds of teen motherhood Effect stronger at lower ages 19

20 Endogenous teen motherhood on worklessness (2 nd stage results, first birth by 17) 20 2SLSLIMLGMM Teen Motherhood (0.188) (0.188) (0.179) Cohort (0.172) (0.172) (0.171) Cohort Squared (0.217) (0.217) (0.215) Cohort Cubic (0.158) (0.159) (0.162) Age * (0.152) (0.152) (0.151) Age Squared * (0.024) (0.024) (0.024) Wales (0.006) (0.006) (0.007) London (0.006) (0.006) (0.006) South-east England (0.007) (0.007) (0.007) Survey Year DummiesYes

21 Endogenous teen motherhood on worklessness (1 st stage results and diagnostic test, first birth by 17) 21 2SLSLIMLGMM RoSLA (0.006) (0.006) (0.006) Born in March-August (0.002) (0.002) (0.002) F-stat for excl. IVs (0.000) (0.000) (0.000) C.V. for 10% rel. bias C.V. for 15% rel. bias Sargan (Anderson-Rubin /Hansen) χ 2 (1) (P-value) (0.675) (0.675) (0.668) Sample Size64,707

22 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) 22

23 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 doesnt seem to matter – at least for this outcome 23

24 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? 24

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