Joint versus sole custody after divorce: Causal effects on child outcomes and family environment
Statistics and Econometrics
Final Report Abstract
This project provides new causal evidence on how joint versus sole custody arrangements affect parents and children after divorce. Custody arrangements play a crucial role in shaping family life after divorce, as they determine the extent of each parent's involvement in their child's life. While many Western countries increasingly promote joint custody, there is limited rigorous evidence on its actual effects. This gap largely reflects limited data and selection bias, which hinder isolating the effects of custody arrangements from family characteristics. We address these challenges by studying the vast majority of custody cases in Sweden over a thirty-year period, leveraging a distinctive institutional feature: custody cases are randomly assigned to judges who differ systematically in their likelihood of awarding joint custody. To enable this analysis, we undertook an extensive data collection effort, assembling a unique dataset that links hand-collected custody rulings from Swedish district courts with detailed administrative records on family background, education, income and health. This combination of legal and administrative data allows us to examine a broad range of outcomes for both parents and children. We use a two-stage least squares (2SLS) instrumental variables approach, with the assigned judge’s tendency to award joint custody serving as an instrument. This design enables us to compare similar families who received different custody outcomes purely due to the random assignment of judges, providing credible estimates of the causal effects of joint versus sole custody. First, joint custody raises children’s test scores and increases their chances of attending high-quality primary schools. It does not affect their mental health. Second, the largest effects are for fathers. Their earnings rise, and they are less likely to use antidepressants or anti-anxiety medication. Third, there is no significant effect on mothers’ earnings or mental health. These findings highlight the importance of maintaining parental involvement after divorce, especially for fathers. In 79 % of sole custody cases, fathers lose all contact with their children, with lasting effects on their economic stability and mental health. Promoting joint custody may therefore not only benefit children’s educational outcomes but also support the broader social and economic achievements of fathers after divorce.
