3 papers
econ.EM2026
Which Policy Works, and Where? Estimation and Inference for State-Level Treatment Effects in Difference-in-Differences
Nichole Austin, Sunny R. Karim, Erin Strumpf +1
Policies with a common objective and implementation date may differ in details or context. We distinguish the aggregate average treatment effect on the treated (ATT) from sub-aggre…
econ.EM2026
Improved Inference for CSDID Using the Cluster Jackknife
Sunny R. Karim, Morten Ørregaard Nielsen, James G. MacKinnon +1
Obtaining reliable inferences with traditional difference-in-differences (DiD) methods can be difficult. Problems can arise when both outcomes and errors are serially correlated, w…
econ.EM2024
Good Controls Gone Bad: Difference-in-Differences with Covariates
Sunny Karim, Matthew D. Webb
This paper introduces the two-way common causal covariates (CCC) assumption, which is necessary to get an unbiased estimate of the ATT when using time-varying covariates in existin…