Welfare of Competitive Price Discrimination with Captive Consumers

We study the welfare effects of price discrimination in a duopoly with both captive and contested consumers. Using a unified information design approach, we characterize the best and worst market segmentations for producer surplus, consumer surplus, and social surplus. The firm-optimal segmentation, which divides the market into two nested segments, consistently reduces consumer welfare relative to uniform pricing. The consumer-optimal segmentation, which divides the market into a symmetric segment and a nested segment, may sometimes yield a Pareto improvement but does not necessarily coincide with the social-optimal segmentation. (JEL D43, D83)