We study the costs and benefits of selling data to a competitor. Although selling all consumers' data may decrease total firm profits, there exist other selling mechanisms -- in which only some consumers' data is sold -- that render both firms better off. We identify the profit-maximizing mechanism, and show that the benefit to firms comes at a cost to consumers. We then construct Pareto-improving mechanisms, in which each consumers' welfare, as well as both firms' profits, increase. Finally, we show that consumer opt-in can serve as an instrument to induce firms to choose a Pareto-improving mechanism over a profit-maximizing one.

翻译：我们研究了向竞争对手出售数据的成本与收益。尽管出售所有消费者的数据可能会降低企业总利润，但存在其他出售机制——即仅出售部分消费者的数据——使得双方企业状况均得以改善。我们识别了利润最大化的机制，并表明企业获得的收益是以消费者利益为代价的。随后，我们构建了帕累托改进机制，在该机制下每位消费者的福利以及两家企业的利润均有所提升。最后，我们证明消费者选择加入机制可作为一种工具，促使企业选择帕累托改进机制而非利润最大化机制。