We provide an overidentification test for a nonparametric treatment model where individuals are allowed to select into treatment based on unobserved gains. Our test can be used to test the validity of instruments in a framework with essential heterogeneity (Imbens and Angrist 1994). The...

This paper aims at formulating econometric tools for investigating stochastic rationality, using the Random Utility Models (RUM) to deal with unobserved heterogeneity nonparametrically. Theoretical implications of the RUM have been studied in the literature, and in particular this paper utilizes...