When Can We Use Two-Way Fixed Effects (TWFE)? A Comparison of TWFE and Novel Dynamic Difference-in-Differences Estimators
The conventional two-way fixed effects (TWFE) estimator has come under increasing scrutiny in settings with staggered treatment adoption. Recent research shows that TWFE can be biased when treatment effects vary across time or groups, prompting the development of several alternative dynamic difference-in-differences (D...