Fertility and labour market outcomes - evidence from prenatal screening information

In this paper I study the labour market effects of having additional children. I find a limited impact of going from two to three children using a novel source of exogenous variation in family size stemming from prenatal screening information. In a regression discontinuity design I compare women across the age 35 threshold in Danish prenatal screening guidelines at which women where informed of their age related risk of having a child with Downs syndrome. Women just over the threshold during the pregnancy for their second child reduced subsequent fertility by 15% but had similar labour market outcomes 1 to 10 years following the birth of the second child. Using twinning and the sex-composition as instruments for fertility I find similarly small effects of the third child. This is robust evidence of the external validity of the limited impact of fertility at the intensive margin as the three strategies applies to different compliers.