This paper analyzes the relative efficiency of a competitive equilibrium against Cournot oligopoly and monopoly equilibria when firms have diverse private information about the stochastic market demand. When firms have information of the same precision, the competitive equilibrium yields a larger expected welfare. However, when information is costly, Cournot oligopoly and monopoly firms acquire more information and, hence, may yield a larger expected welfare than the competitive firms under certain conditions. The author also finds that competitive firms acquire less than the efficient level of information while Cournot oligopoly and monopoly firms may acquire more than the efficient level. Copyright 1995 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.
International Economic Review