We study what kind of equilibria of which mechanisms are ex post renegotiation-proof (EPRP), i.e., robust against the possibility of ex post renegotiation under a variety of renegotiation procedures, and which social choice functions are EPRP implementable. In complete information environments...

We derive a bound on the seller’s relative revenue loss from an unanticipated bidders’ collusion in the optimal auctions. Under the standard hazard rate assumption the relative loss is at most 1 3 when there are just two bidders. The measure of the loss is increasing with the number of...

We study the principal’s optimal response to collusion in an adverse selection environment. Building on the framework of Laffont and Martimort (1997, 2000) we advance it into several directions. First, unlike most of the literature, we study a stronger collusion when the agents can coordinate...

We study a problem of a multiproduct monopolist selling substitutable goods to a buyer with unknown valuations. Under the standard distributional assumptions we find that in the optimal menu every nontrivial contract delivers some good with certainty. Using this result we apply control-theoretic...

This paper studies communication in a static Cournot duopoly model under the assumption that the firms have unverifiable private information about their costs. We investigate the conditions under which the firms cannot transmit any information through cheap talk, and show that when these...

We study cheap-talk pre-play communication in the static all-pay auctions. For the case of two bidders, all correlated and communication equilibria are payoff equivalent to the Nash equilibrium if there is no reserve price, or if it is commonly known that one bidder has a strictly higher value....

We compare three common dispute resolution processes - negotiation, mediation, and arbitration - in the framework of Crawford and Sobel [V. Crawford, J. Sobel, Strategic information transmission, Econometrica 50 (6) (1982) 1431-1451]. Under negotiation, the two parties engage in (possibly...

We analyze the performance of various communication protocols in a generalization of the Crawford-Sobel (1982) model of cheap talk that allows for multiple receivers. We find that the sender prefers communicating by private messages if the receivers' average bias is high, and by public messages...

We study communication in a static Cournot duopoly model under the assumption that the firms have unverifiable private information about their costs. We show that cheap talk between the firms cannot transmit any information. However, if the firms can communicate through a third party,...