The effects of motherhood∗

We use miscarriage as a biological shock to fertility in order to estimate the causal impact of motherhood on labor market outcomes. The number of instruments is increased by exploiting the response-heterogeneity to miscarriage along three dimensions: time, age, and birth order. This allows us to separately identify the effect of the first, second and third child as well as the effects of pregnancy and caretaking for small children. We find each child reduces female earnings by around 18%, only part of it due to reduced work hours. We find no evidence of an adverse health effect of having children. JEL Classification: C26, I10, J13, J22 ∗We want to thank Sara Cools, Simen Gaure, Jo Thori Lind, Kalle Moene, Magne Mogstad, Ole Røgeberg, Ragnhild Schreiner and Kjetil Storesletten for their help, advice and suggestions. This paper is a part of the projects ”Absenteeism Disability, Norms and Interventions” (grant 201416), ”Disentangling absence patterns” (grant 227103) and ”Understanding the gender gap in sickness absence” (grant 218378), financed by the Norwegian Research Council. Data made available by Statistics Norway have been essential for the research project. It is also part of the research activities at the Center of Equality, Social Organization, and Performance (ESOP) at the Department of Economics at the University of Oslo. ESOP is supported by the Research Council of Norway. †Ragnar Frisch Centre for Economic Research. E-mail: [email protected] ‡Institute for Social Research and ESOP, University of Oslo. E-mail: [email protected]