We use data on over 420,000 first-time Dutch mothers to examine the effects of postpartum antidepressant use. Dutch general practitioners (GPs) must be available for house calls. We therefore instrument a woman’s receipt of antidepressants postpartum with local practitioners’ propensity to prescribe antidepressants to women 46 to 65. Ordinary least squares suggests negative effects of postpartum antidepressants but this is due to selection into treatment. Instrumental variables estimates indicate that the marginal treated patient is likely to continue taking antidepressants long term and is less likely to be employed in the year after birth, with little evidence of other effects.

The last 40 years have seen huge innovations in computing and in the availability of data. Data derived from millions of administrative records or by using (as we do) new methods of data generation such as text mining are now common. New data often requires new methods, which in turn can inspire new data collection. If history is any guide, some methods will stick and others will prove to be a flash in the pan. However, the larger trends toward demanding greater credibility and transparency from researchers in applied economics and a 'collage' approach to assembling evidence will likely continue.

Working Papers

This paper presents new causal evidence on the “power” of oral contraceptives in shaping women’s lives, leveraging the 1970 liberalization of the Pill for minors in the Netherlands and demand- and supply-side religious preferences that affected Pill take-up. We analyze administrative data to demonstrate that, after Pill liberalization, minors from less conservative areas were more likely to delay fertility/marriage and to accumulate human capital in the long run. We then show how these large effects were eliminated for women facing a higher share of gatekeepers – general practitioners and pharmacists – who were opposed to providing the Pill on religious grounds.

This paper explores the effects of the Great Depression and World War II (WWII) on lifecycle fertility. In the Netherlands, an immediate and unprecedented baby boom followed the end of WWII and the baby bust of the 1930s. It is unclear whether the war and depression just shifted the timing of fertility or changed women’s completed fertility. I combine administrative data on births with historical data and show that women experienced the crisis and war at different ages and differentially across locations. This variation in the timing and spacing of these events across maternal birth cohorts is exploited to estimate counterfactual densities of births using a bunching methodology. I show that the rise in fertility after the liberation did not make up for the “missed” births that did not occur because of the war and depression. Further, the Great Depression had a larger effect on lifecycle fertility than WWII. For women in prime fertile ages during the depression, these “missed” births can be explained by higher childlessness and the formation of smaller families. These findings shed new light on the importance of economic factors in influencing fertility decisions.

This paper aims to better understand the persistence of gender gaps in adult economic outcomes by studying the influence of pre-birth factors on educational performance early in life. We exploit natural variation in prenatal testosterone exposure between fraternal twins. Such exposure has been shown to affect the organization of the brain in the developing fetus. The twin design helps control for postnatal factors and we also examine interactions between prenatal exposure and postnatal factors. Girls with a twin brother have higher mean birth weights than girls with a twin sister, leading us to predict that they should have higher test scores. However, they lag behind their brothers in terms of math scores by the end of primary school. Our findings suggest that post-birth factors are driving this result, and that these offset any direct biological advantage of prenatal testosterone on test scores. Overall, these results suggest that gender differences in test scores are strongly socially determined.

Works in Progress

Publications in Dutch