Many couples marry either just before or soon after they have their first child. I show that married couples who have the first child before or in the year of marriage (kids-first) divorce around twice more often than those having their first kids in the year following their marriage or later (marriage-first). Various well-known determinants of divorce do not explain this difference. I show that this finding is consistent with a simple setup where people choose whether to marry based on their potential relationship quality. Unplanned pregnancies can affect their decisions as women face a risk of raising the child alone. I build and estimate a lifecycle model replicating the difference in divorce rates and use it for policy analysis. First, promoting marriage results in higher divorce rates and lower welfare, and marriage rates themselves respond little to monetary incentives. Second, forcing fathers to pay child support has a mild impact on couples’ marriage and divorce decisions, although it incentivizes more women to be single mothers. Third, policies that improve people’s ability to control their fertility result in better marriages, less divorce, and higher welfare.

What is the role of unilateral divorce for the rise of unmarried cohabitation? Exploiting the staggered introduction of unilateral divorce across the US states, we show that after the reform singles become more likely to cohabit than to marry, and newly formed cohabitations last longer. To understand the mechanisms underlying these facts, we build a life-cycle model with partnership choice, endogenous divorce/breakup, female labor force participation, and saving decisions. Structural estimation that matches the empirical findings suggests that unilateral divorce decreases marriage gains stemming from cooperation and risk-sharing. This makes cohabitation preferred to couples that would have likely faced a divorce, which is more expensive than breaking up. As cohabiting couples formed after the reform are better matched, the average length of cohabitations increases by 27%. Consistent with data, the rise of cohabitation is larger in states that impose an equal division of property as men, fearing to lose most of their assets upon divorce, convince women to cohabit in exchange for more household resources. A counterfactual experiment reveals that the time spent cohabiting would have been halved if the divorce laws had never changed.

“Fighting the Biology: Reproductive Technologies and Female Labor Supply”, work in progress