We study the design of profit maximizing single unit auctions under the assumption that the seller needs to incur costs to contact prospective bidders and inform them about the auction. With independent bidders’ types and possibly interdependent valuations, the seller’s problem can be...

This paper examines the ability of a policy maker to control equilibrium outcomes in a global coordination game; applications include currency attacks, bank runs, and debt crises. A unique equilibrium is known to survive when the policy is exogenously fixed. We show that, by conveying...

This paper investigates the possibility that wealth (holdings of money) serves as a signal of ability to produce high quality products for agents who cannot directly observe the quality of the products. A producer’s wealth may advertise past success in selling products to agents who knew the...

We provide a model to study the effect of improving the quality of the filters that users use, and the increase of the cost of mailing spam messages, on the total number of messages that spammers send. We show that increasing the cost of mailing spam messages have the unequivocal effect of...

The sensitivity of Nash equilibrium to strategic and informational details presents a diØ culty in applying it to games which are not fully specified. Structurally-robust Nash equilibria are less sensitive to such details. More-over, they arrise naturally in important classes of games that have...

This paper studies the exchange of information between two principals who contract sequentially with the same agent, as in the case of a buyer who purchases from multiple sellers. We show that when (a) the upstream principal is not personally interested in the downstream level of trade, (b) the...

In games with costly signaling, some equilibria are vulnerable to deviations which could be "unambiguously" interpreted as coming from a unique set of Sender-types. This occurs when these types are precisely the ones who gain from deviating for any beliefs the Re-ceiver could form over that set....

This paper presents a model of emergent class structure, in which a society inhabited by inherently identical households may be endogenously split into the rich bourgeoisie and the poor proletariat. For some parameter values, the model has no steady state where all households remain equally...

Since campaign finance reform is usually motivated by the concern that existing legislation can not effectively prevent campaign contributions to ‘buy favors’, this paper assumes that contributions influence political decisions. But, given that it is also widely recognized that interest...