Firms' Beliefs and Learning: Models, Identification, and Empirical Evidence

This paper reviews recent literature on structural models of oligopoly competition where firms have biased beliefs about the primitives of the model-e.g. demand, costs-or about the strategic behavior of other firms in the market. We describe different structural models that have been proposed to study this phenomenon and examine the approaches that have been used to identify firms' beliefs. We discuss empirical results in recent studies and show that accounting for firms' biased beliefs and learning can have important implications on our measures and interpretation of market efficiency.