Dynamic Joint Decisions: Free-Riding, Multi-Issue Bargaining, and Contract Revision

西北大学SBR-9511953该提案由三个相关的项目组成，以合同的修订和协议和行动的有意顺序为中心。第一个项目检验了这样一个假设：当合同无法执行时，各方可能需要随着时间的推移逐步采取行动。这一观点的一个应用涉及自愿为公共物品捐款的经典案例。如果贡献者必须同时捐款，那么唯一的平衡结果是没有捐款，因为每个人都试图“搭便车”。但是，如果个人可以在一段时间内分散他们的贡献，一般就会存在一种均衡，即在有限的时间内完成全部贡献。本研究将探讨这一结果对所作基本假设的稳健性。第二个项目着眼于并非所有行动都是可收缩的情况下的多问题谈判。同样，我们的目标是理解为什么合同协议经常以零敲碎打的方式达成，而当前的模型预测，所有事情都应该在一开始就进行谈判，不能拖延。第三个项目涉及合同协议的演变。本文提出的模型表明，在有限责任约束下的委托代理模型中，均衡初始合同采用简单债务的形式，然后进行重新谈判。

Steven Matthews Northwestern University SBR-9511953 The proposal consists of three related projects centered on the revision of contracts and the intentional sequencing of agreements and actions. The first project examines the hypothesis that when contracts cannot be enforced, then the parties may need to take actions piecemeal over time. One application of this idea concerns the classic case of voluntary contributions to a public good. If contributors have to give at the same time, then the only equilibrium results in no contributions being given as everyone tries to "free-ride." But if individuals can spread out their contributions over time, in general an equilibrium will exist in which full contributions are made in finite time. The research will explore the robustness of this result to the underlying assumptions made. The second project looks at multi-issue bargaining when not all actions are contractible. Again the goal is to understand why contractual agreements are often reached in piecemeal fashion, when current models predict that everything should be negotiated at the beginning with no delay. The third project concerns the evolution of contractual agreements. A model is presented that suggests that in a principal-agent model in which contracts are contrained by limited liability, the equiibrium initial contract takes the form of simple debt which is later renegotiated.