Many commonly used treatment effects estimators rely on the unconfoundedness assumption ("selection on observables") which is fundamentally non-testable. When evaluating the effects of labor market policies, researchers need to observe variables that affect both treatment participation and labor...

We study how website defaults affect consumer behavior in the domain of charitable giving. In a field experiment that was conducted on a large platform for making charitable donations over the web, we exogenously vary the default options in two distinct choice dimensions. The first pertains to...