Black, Dan A.; Joo, Joonhwi; LaLonde, Robert; Smith, … - 2017
We provide simple tests for selection on unobserved variables in the Vytlacil-Imbens-Angrist framework for Local … Average Treatment Effects. The tests allow researchers not only to test for selection on either or both of the treated and … untreated outcomes, but also to assess the magnitude of the selection effect. The tests are quite simple; undergraduates after …