We consider the second price sealed bid auction of an object that the potential buyers value privately and independently. We show that a cartel?s ex ante optimum, subject to incentive compatility and ex post balanced transfers, coincides with the first best and defines a supermodular...

Nous considérons la vente aux enchères sous pli scellé au second prix d'un objet que chaque acquéreur potentiel évalue de manière « privée et indépendante ». Nous montrons que l'optimum ex ante d'un cartel, sous contraintes d'incitation et d'équilibre ex post des transferts, coïncide...

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...

If the allocations of a differential information economy are defined as incentive compatible state-contingent lotteries over consumption goods, competitive equilibrium allocations exist and belong to the (ex ante incentive) core. Furthermore, any competitive equilibrium allocation can be viewed...

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...

In a differential information economy with quasi–linear utilities, monetary transfers facilitate the fulfillment of incentive compatibility constraints : the associated ex ante core is generically nonempty. However, we exhibit a well–behaved exchange economy in which this core is empty, even...