Recent Advances in the Theory of Third-Degree Price Discrimination: A Brief Survey

This survey provides a selected review of the recent progress in the theory of third-degree price discrimination. First, I focus on two well-known results in the literature: (i) an increase in aggregate output is necessary for price discrimination to increase social welfare, and (ii) price discrimination leads to a Pareto welfare improvement if one of the two markets is not served under uniform pricing. I argue when these results hold and when they fail to hold. Second, I consider oligopolistic competition and stress that there is no great divide between monopoly and oligopoly because both situations can be treated systematically in terms of an index that governs the intensity of competition.