Elchanan Ben-Porath,  Eddie Dekel, Barton L. Lipman

First draft June 2016

Current draft January 2017, under revision for Econometrica

Abstract :

We show that in a class of I–agent mechanism design problems with evidence, commitment has no value for the principal, randomization has no value for the principal, and robust incentive compatibility has no cost. In particular, there is an equilibrium with a relatively simple structure in which the principal obtains the same outcome without commitment as the best he can achieve with commitment.