Julius Ilciukas

This paper develops a new methodology to estimate the labor market effects of parenthood, using quasi-experimental variation from intrauterine insemination procedures. Conventional instrumental variable estimates may be biased because childbirth often follows failed procedures, meaning that success may affect outcomes through both the incidence and timing of parenthood. I leverage women’s complete procedure histories to address this bias and estimate effects for a broader, policy-relevant population. Using Dutch administrative data, I find that parenthood leads to persistent reductions in women’s earnings (10–28%) and work hours (10–22%), causing up to half of the within-couple gender inequality observed after childbirth.

We estimate the impact of having siblings on the cognitive and non-cognitive development of first-born children. By exploiting quasi-experimental variation in the sequence of parents' in vitro fertilization (IVF) attempts for a second child, we identify effects for first-born children who would remain only children if all IVF attempts fail. Using Danish administrative registers linked to nationwide school surveys, we find that siblings have little effect on test performance (math and reading), personality traits (conscientiousness, agreeableness, emotional stability), or classroom and school well-being. Overall, we conclude that having siblings neither harms nor spurs the first-borns' cognitive and non-cognitive development.

I study how reduced retirement opportunities in one generation affect fertility in the subsequent generation. I use administrative Dutch data and exploit the 2006 Dutch pension reform, which induced individuals born from January 1, 1950 onward to delay retirement while exempting those born earlier. I find that this reform reduced fertility among women with affected mothers. The reduction is economically significant and persists after the impact on retirement fades out. I supplement my analysis with survey evidence and argue that the fertility reduction can be explained by reduced grandparental child care supply.