Third‐Degree Price Discrimination in Oligopoly when Markets are Covered*

We analyze oligopolistic third-degree price discrimination relative to uniform pricing when markets are covered. Pricing equilibria critically determined by supply-side features such as the number of firms and their marginal cost differences. It follows that each firm's Lerner index under is equal weighted harmonic mean margins discriminatory pricing. Uniform then lowers average prices raises consumer surplus. can calculate gain in surplus loss firms' profits from based only on market data equilibrium (i.e., quantities).