We study auctions for an indivisble object. The outcome of the auction influences the future interaction among agents. The impact of that interaction on agent i is assumed to be a funciton of the agents' valuations. While agent's i valuation is private information to i, other valuations are not...

We study efficient, Bayes-Nash incentive compatible mechanisms in a general social choice setting that allows for informationally interdependent valuations and for allocative externalities. We show that such mechanisms exist only if a congruence condition relating private and social rates of...