The article develops a bargaining model of spatial competition. Sellers compete by choosing locations in a market region. Consumers face a cost to moving from one place to another. The price of the good is determined as the perfect equilibrium of a bargaining game between seller and buyer. In this game, the buyer has the outside option to move to another seller and so the prices at all stores are interdependent. Existence of a location-price equilibrium is established. The outcome approaches the perfectly-competitive one if the consumer's cost of traveling becomes negligible or if the number of sellers tends to infinity. Copyright 1989 by The Econometric Society.

This paper extends the revelation principle to environments in which the mechanism designer cannot fully commit to the outcome induced by the mechanism. We show that he may optimally use a direct mechanism under which truthful revelation is an optimal strategy for the agent. In contrast with the conventional revelation principle, however, the agent may not use this strategy with probability one. Our results apply to contracting problems between a principal and a single agent. By reducing such problems to well-defined programming problems they provide a basic tool for studying imperfect commitment.