We present a new approach to the theory of imperfect competition and apply it to study price competition among differentiated products. The central result provides general conditions under which there exists a pure strategy price equilibrium for any number of firms producing any set of products....

This paper analyzes price fixing by the Joint Executive Committee railroad cartel from 1880 to 1886 and develops tests of two game-theoretic models of tacit collusion. The first model, due to Abreu, Pearce and Stacchetti (1986), predicts that price will switch across regimes according to a...

We study collusive behaviour in experimental duopolies that compete in prices under dynamic demand conditions. In one treatment the demand grows at a constant rate. In the other treatment the demand declines at another constant rate. The rates are chosen so that the evolution of the demand in...

We study the relation between the number of firms and market power in experimental oligopolies. Price competition under decreasing returns involves a wide interval of pure strategy equilibrium prices. We present results of an experiment in which two, three and four identical firms repeatedly...

We study the relation between the number of firms and price-cost margins under price competition with uncertainty about competitors' costs. We present results of an experiment in which two, three and four identical firms repeatedly interact in this environment. In line with the theoretical...