We show that, in environments with independent private values and transferable utility, a privately informed principal can solve her mechanism selection problem by implementing an allocation that is ex-ante optimal for her. No type of the principal can gain from proposing an alternative...

In this paper we address the question of collusion in mechanisms under asymmetric information. We develop a methodology to analyze collusion as an informed principal problem. First, if collusion occurs after the agents accept or reject the principal's offer; the dominant-strategy implementation...