We study the question of collusion in auctions. We start by presenting a model of a first price auction with complete information and direct asymmetric externalities. Following a non-cooperative approach we study the negotiations process which yields a cartel. We show that in the presence of...

We consider two-sided matching markets in which agents have private information on a state of nature which determines the agents' utilities of matching. Monetary transfers are allowed and utility functions are quasi-linear. The model thus extends the assignment game introduced by Shapley and...

The ex ante incentive compatible core of an exchange economy with private information is the (standard) core of a characteristic function which expresses the fact that coalitions allocate goods by means of random incentive compatible mechanisms. We first survey some results in the case of...

We propose two classes of allocation games for N.T.U. and T.U. exchange economies in which initial endowments and preferences depend on the agents’ private information. In both models, agents make non-verifiable claims about their types and effective deposits of consumption goods, which are...

Afriat proved the equivalence of a variant of the strong axiom of revealed preference and the existence of a solution to a set of linear inequalities. From this solution he constructed a utility function rationalizing the choices of a competitive consumer. We extend Afriat's theorem to a class...

This paper characterizes geometrically the sets of all Nash and perfect Bayesian equilibrium payoffs achievable with unmediated communication in persuasion games, i.e., games with an informed expert and an uninformed decisionmaker in which the expert's information is certifiable. The first...

This paper studies the set of equilibria that can be achieved by adding general communication systems to Bayesian games in which some information can be certified or, equivalently, in which players’ types are partially verifiable. Certifiability of information is formalized by a set of...

In a commonvalueauction in which the information partitions of the bidders are connected, all rings are core-stable. More precisely, the ex ante expected utilities of rings, at the (noncooperative) sophisticated equilibrium proposed by Einy et al. [Einy, E., Haimanko, O., Orzach, R., Sela, A.,...