Price Discrimination in Input Markets and Quality Differentiation

This paper examines the welfare implications of input price discrimination in a vertically-related market, which is composed of a monopolistic upstream market and a duopolistic downstream market. The downstream duopolists produce quality-differentiated products at different marginal costs. We show that the equilibrium input prices are closely related to the downstream quality gap and cost difference. When the monopolist simply charges a unit wholesale price for its input product, discriminatory pricing could be socially desirable even though the aggregate output remains unchanged. Nevertheless, if a two-part tariff is feasible, then banning price discrimination could increase the aggregate output and social welfare.