Games and Economic Behavior · 2026 · Rodrigo Bomfim Andrade、Henrique Castro-Pires、Humberto Moreira
中文摘要
我们分析当供应商随时间推移逐渐了解项目成本并保留事后退出权时的最优采购合同。在第一期,企业观察到关于高成本发生可能性的私人信号;在第二期,其了解到实现的成本类型,并决定是继续履约还是行使外部选择权。我们证明,当退出机会足够有吸引力时,最优机制会混同所有第一期信号,并简化为成本加成合同,其中支付仅与实现的、可验证的成本挂钩。事前诱导企业给出成本预测的尝试会适得其反:企业策略性地低报预期,在高成本状态下触发退出,并导致成本超支。这为成本超支提供了一种基于机制的解释,即成本超支源于激励设计的失败。最后,我们证明更慷慨的外部选择权可能提高采购成本并降低企业利润,并识别出限制退出权在事前构成帕累托改进的条件。(JEL D82, D86, H57)
Abstract
We analyze optimal procurement contracts when suppliers learn about project costs over time and retain an ex-post right to exit. In the first period, the firm observes a private signal on the likelihood of high costs; in the second, it learns the realized cost type and decides whether to continue or exercise its outside option. We show that when exit opportunities are sufficiently attractive, the optimal mechanism pools all first-period signals and reduces to a cost-plus contract, with payments tied only to realized, verifiable costs. Attempts to elicit cost forecasts ex-ante backfire: firms strategically under-report expectations, triggering exit in high-cost states and generating overruns. This provides a mechanism-based interpretation of cost overruns as failures of incentive design. Finally, we demonstrate that more generous outside options can raise procurement costs and lower firm profits, identifying conditions where limiting exit rights is ex-ante Pareto improving. (JEL D82, D86, H57)