Two-part pricing with costly arbitrage

This paper considers the optimal two-part pricing strategy of a monopolist whose customers collude when they purchase the firm's product. In contrast to the sentiment in the existing price discrimination literature, I find that a monopolist's profit can actually increase when consumers share its good. When transaction costs for collusion are zero the firm can extract the full consumer surplus through two-part prices. When transaction costs are positive or there are a substantial number of consumers without access to resale, the firm may be hurt by arbitrage.