Optimal robust allocation of private goods

We characterize the optimal robust mechanisms for the allocation of private objects, where robust mechanisms are those mechanisms that satisfy dominant strategy incentive compatibility, ex-post individual rationality, and ex-post no budget deficit, and optimal robust mechanisms are the ones that maximize the expected sum of players’ payoffs among all robust mechanisms. With a certain assumption on the payoff of the lowest possible type, we provide a complete description of optimal robust mechanisms with any number of players and objects.