Can an Increase in the Minimum Age of Marriage Reduce Child Marriage Rates? Evidence from Mexico

We provide empirical evidence on the impact of raising the minimum age of marriage to 18 years old on child marriage, early motherhood, and school enrollment in Mexico. Using a difference-in-differences model that takes advantage of the staggered adoption of this reform across states, we show that banning child marriage leads to a large and statistically significant reduction in the number of registered child marriages. However, we find no effect on the share of girls enrolled in school or the rate of early fertility. We also find that in births with mothers below the age of 18, the drop in the share of formally married mothers as a consequence of the reform is neutralized by an increase in the share of mothers in informal unions. These findings suggest that in places where informal unions are common, raising the minimum age of marriage is not enough to prevent early unions, motherhood, and school dropout.