Estimation of Heterogeneous Treatment Effects Using Quantile Regression with Interactive Fixed Effects

We study the estimation of heterogeneous effects of group-level policies, using quantile regression with interactive fixed effects. Our approach can identify distributional policy effects, particularly effects on inequality, under a type of difference-in-differences assumption. We provide asymptotic properties of our estimators and an inferential method. We apply the model to evaluate the effect of the minimum wage policy on earnings between 1967 and 1980 in the United States. Our results suggest that the minimum wage policy has a significant negative impact on the between-inequality but little effect on the within-inequality.