FEDS Paper: An Evaluation of Difference-in-Differences Methods Using Placebo Event Studies
John Coglianese and Jade A. FangResearchers are faced with the choice of which of the many recently developed difference-in-differences methods to use in practice. To assess these estimators' relative performance for single-unit event studies, we conduct 134,000+ state-level placebo event studies across 13 estimators. We find that no single method dominates.