Doubly Robust Estimation of Treatment Effects in Staggered Difference-in-Differences with Time-Varying Covariates
时变协变量下交错双重差分处理效应的双重稳健估计
With staggered adoption, difference-in-differences (DiD) analyses define the average treatment effect on the treated (ATT) at the group-period level and aggregate it into groupwise, periodwise, dynamic, and overall effects. We study a period-by-period version of conditional parallel trends, with covariates unaffected by treatment while allowing covariates to shift the trends in untreated potential outcomes. We propose an augmented inverse probability weighting (AIPW)…