The Fragility of Estimated Effects of Unilateral Divorce Laws on Divorce Rates

Following an influential article by Friedberg (1998) on the response of divorce rates to the adoption of unilateral divorce laws, Wolfers (2006) explored the sensitivity of Friedberg's results to allowing for dynamic response. We in turn explore the sensitivity of Wolfers's results to variations in estimation method and functional form, and we find that the results are extremely fragile. We conclude first that the impact of unilateral divorce laws remains unclear. Second, we make the methodological point that identification in differences-in-differences research becomes weaker in the presence of dynamics, especially in the presence of unit-specific time trends.