In these supplementary materials we provide some details on the implementation of the methods developed in the paper. In addition we apply the different DID approaches using the data analyzed by Meyer, Viscusi, and Durbin (1995). These authors used DID methods to analyze the effects of an increase in disability benefits in the state of Kentucky, where the increase applied to high-earning but not low-earning workers. Next we do a small simulation study. Finally, we provide some additional proofs.