Two-person ex post implementation

This paper investigates the ex post implementation of a social choice set with two agents. A social choice set F is ex post implementable with two agents if F satisfies the conditions of ex post incentive compatibility (EPIC) and ex post monotonicity (EM) in an environment that is economic and has a bad outcome. Furthermore, if F is a social choice function, (EPIC), (EM), and an economic environment are sufficient.