Inattentive Consumers and Product Quality

This paper studies a model in which some consumers shop on the basis of price alone, without attention to potential differences in product quality. A firm may offer a low-quality product to exploit these inattentive consumers. In the unique symmetric equilibrium of the model, firms choose prices with mixed strategies, similarly to Varian (1980) in which some consumers purchase from a random seller without attention to market prices. In our model, though, firms also choose quality stochastically, and there is both price and quality dispersion. Two stylized policy interventions are considered: competition policy, which acts to increase the number of sellers, and market transparency reforms which act to increase the fraction of attentive consumers. With fewer inattentive consumers, firms are less likely to "cheat" (i.e., cut quality) which therefore improves welfare, but profit and consumer surplus can either increase or decrease. When there is a large number of sellers, approximately half the sellers cheat (regardless of the fraction of inattentive consumers), and introducing more sellers boosts consumers surplus and reduces profit, while the impact on welfare is ambiguous.