Customer Poaching and Brand Switching
分析双头垄断市场中企业通过短期或长期合同挖角竞争对手客户的行为，发现消费者偏好固定时短期合同导致社会无效转换，而长期合同可减少转换；偏好独立时短期合同有效，长期合同则转换不足。
Firms sometimes try to poach the customers of their competitors by offering them inducements to switch. We analyze duopoly poaching under both short-term and long-term contracts assuming either that each consumer's brand preferences are fixed over time or that preferences are independent over time. With fixed preferences, short-term contracts lead to poaching and socially inefficient switching. The equilibrium with long-term contracts has less switching than when only short-term contracts are feasible, and it involves the sale of both short-term and long-term contracts. With independent preferences, short-term contracts are efficient, but long-term contracts lead to inefficiently little switching.