We study mechanism design in non-Bayesian settings of incomplete information, when the designer has no information about the players, and the players have arbitrary, heterogeneous, first-order, and possibilistic beliefs about their opponents' payoff types.

I study collusion between two bidders in a general symmetric IPV repeated auction, without communication, side transfers, or public randomization. I construct a collusive scheme, endogenous bid rotation, that generates a payoff larger than the bid rotation payoff.

We show that collusion and wrong beliefs may cause a dramatic efficiency loss in the Vickrey mechanism for auctioning a single good in limited supply. We thus put forward a new mechanism guaranteeing efficiency in a very adversarial collusion model, where the players can partition themselves...

This paper shows that a cartel that observes neither costs, prices, nor sales may still enforce a collusive agreement by tying each firm's continuation profit to the truncated current profits of the other firms. The mechanism applies to both price and quantity competition, and the main features...

In a Markov game, players engage in a sequence of games determined by a Markov process. In this setting, this paper investigates the impact of varying the informativeness of public information, as defined by Blackwell [8,9], pertaining to the games that will be played in future periods. In...

We provide a new sufficient condition for the robustness of sets of equilibria to incomplete information in the sense of Kajii and Morris (1997) [11], Morris and Ui (2005) [15]. The condition is formulated for games with a saddle function. A saddle function is a real-valued function on the set...

In an exchange economy with incomplete information, the signaling core is defined by the set of state-contingent allocations to which no coalitions object under informational leakage through proposals by informed agents. An objection underlying the signaling core is supported by a sequential...

Harsányi [4] showed that Bayesian games over finite games of payoff uncertainty with finite sets of belief types always admit Bayesian equilibria. That still left the question of whether Bayesian games over finite games of payoff uncertainty with infinitely many types are guaranteed to have...