DiD – Healthcare Economist

Should we trust staggered difference-in-differences estimates?

2023-03-20Jason Shafrin

That is the question posed in paper by Baker, Larcker and Wang (2022). I summarize their key arguments below. The validity of…[the DiD]…approach rests on the central assumption that the observed trend in control units’ outcomes mimic the trend in treatment units’ outcomes had they not received treatment. As the authors write: First, DiD estimates…

The problem with propensity score matching when using difference-in-difference

2018-11-09Jason ShafrinLeave a comment

Difference-in-differences attempts to measure causal effects using changes in outcomes across different groups. One of the key assumptions of differences-in-differences specification are that pre-period trends are similar across these groups. But what happens if these pre-period trends do appear? Can the use of propensity score matching solve the problem. According to a paper by Daw…