How does cost uncertainty affect the welfare consequences of an oligopoly? To answer this question, we investigate a Cournot oligopoly in which firms produce a homogeneous commodity and market entry is feasible. Marginal costs are unknown ex-ante, i.e. prior to entering the market. They become...

We study a model where capacity installation by an incumbent firm serves to deter others from entering the industry. We argue that uncertainty about demand or costs forces the incumbent to choose a higher capacity level than it would under certainty. This higher level diminishes the...