🤖 AI Summary
This paper addresses the challenge of estimating dynamic causal effects in event-study settings featuring non-binary, non-absorbing, and multiply time-varying treatments. We propose a dynamic multi-group difference-in-differences (DID) framework that relaxes conventional event-study assumptions—namely, binary, single, and irreversible treatment assignment—and jointly accommodates four complex treatment structures: switchable binary treatments, continuous absorbing treatments, discrete multi-valued reversible treatments, and temporally nested double-binary absorbing treatments. Our method enables dynamic decomposition of treatment paths and robust identification via the newly developed Stata command `did_multiplegt_dyn`. We validate its efficacy and generalizability across four empirical applications, demonstrating substantial improvements in estimation accuracy and interpretability of dynamic treatment effects under intricate intervention regimes.
📝 Abstract
The command did_multiplegt_dyn can be used to estimate event-study effects in complex designs with a potentially non-binary and/or non-absorbing treatment. This paper starts by providing an overview of the estimators computed by the command. Then, simulations based on three real datasets are used to demonstrate the estimators' properties. Finally, the command is used on four real datasets to estimate event-study effects in complex designs. The first example has a binary treatment that can turn on an off. The second example has a continuous absorbing treatment. The third example has a discrete multivalued treatment that can increase or decrease multiple times over time. The fourth example has two, binary and absorbing treatments, where the second treatment always happens after the first.