A Simple Approach to Staggered Difference-in-Differences in the Presence of Spillovers

We establish identifying assumptions and estimation procedures for the ATT in a Difference-in-Differences setting with staggered treatment adoption in the presence of spillovers. We show that the fully interacted TWFE regression approach of Wooldridge [2022] can be extended to our proposition. We broaden our framework to the non-linear case of count data and revisit a corresponding application from the crime literature. Monte Carlo simulations show that our estimator performs competitively.