The Economics of Self Control, and the Evolution of Equilibrium

智力优势：在之前的研究中，Levine和Fudenberg提出了一个冲动控制的“双我”模型，并认为它提供了一种易于处理和简约的方式来解释通常用于激发准双曲线偏好的事实，例如货币奖励选择的时间不一致性和过度拖延。该项目将相同的模型应用于一系列新的应用，包括Allais悖论，该悖论依赖于决策理论的“独立公理”，而这正是双自模型预测的方式。该项目还开发了预测和实证测试，区分标准，双自我和准双曲线偏好。部分B）该项目这一部分的出发点是，游戏中的均衡最好理解为学习，模仿或进化的非均衡动态过程的长期结果。 该项目侧重于两个进程，其适用范围和结论明显不同。 研究的第一个过程是智能体的理性学习过程，智能体利用对过去游戏的观察来形成对对手未来可能如何游戏的信念。 以前的工作依赖于简化的假设，即所有代理人在一个给定的球员角色接收相同的信号，并有相同的信念;该项目确定时，简化是有效的。第二个过程研究的是有限理性模仿或“糊涂”，其中代理人往往复制策略与更高的当前收益。 大多数关于进化过程的工作都集中在无限种群的情况下，特别是在“复制动态”，但这个模型的长期结果并不总是一个很好的近似结果时，人口是大的，但有限的。 建议的研究有助于确定当人口规模增长时，极限结果收敛到复制因子动态的预测。 这一结果，然后应用到合作的进化稳定性的研究时，代理人可以从一个社会迁移到另一个。 重点是什么时候进化的力量会导致不信任外来者的“封闭”社会，什么时候社会会“开放”。更广泛的影响：（A）行为经济学的思想现在在法学院和法律评论，领先的科学期刊和大众媒体中流行。 然而，第一代行为模型专注于特殊目的的假设，以适应特定的事实，现在是时候发展更系统的行为理论，解释许多与标准模型相同，最好是很少偏离的异常。项目A部分的工作有助于这一议程。(B)博弈均衡的概念被用于许多领域，包括政治学、社会学、计算机科学、生物学和心理学。 因此，该项目对如何从非均衡学习中产生均衡的研究在经济学之外产生了重大影响。 发展有限种群中的进化模型对数学生物学非常重要，并且已经开始引起物理学家的注意。 政治学家、社会学家、生物学家以及经济学家都应该对合作的演变这一特定问题感兴趣。

Intellectual Merit: Part A) In previous work Levine and Fudenberg developed a "dual-self" model of impulse control, and argue that it provides a tractable and parsimonious way of explaining the facts that are typically used to motivate quasi-hyperbolic preferences, such as time-inconsistency in the choice of monetary rewards and excessive procrastination. This project applies the same model to a new set of applications, including the Allais paradox, which relies on the "Independence axiom" of decision theory being violated in precisely the way that the dual-self model predicts. The project also develops predictions and empirical tests that discriminate between the standard, dual-self, and quasi-hyperbolic preferences.Part B) The starting point for this part of the project is that equilibrium in a game is best understood as the long-run outcome of a non-equilibrium dynamic process of learning, imitation, or evolution. The project focuses on two processes with markedly different domains of applicability and conclusions. The first process studied is one of rational learning by agents who use their observations of past play to form their beliefs about how opponents are likely to play in the future. Previous work has relied on the simplifying assumption that all agents in a given player role receive the same signals and have the same beliefs; the project determines when that simplification is valid.The second process studied is one of boundedly rational imitation or "muddling," where agents tend to copy strategies with higher current payoffs. Most work on evolutionary processes has focused on the case of infinite populations, and in particular on the "replicator dynamic," but the long-run outcome of this model is not always a good approximation to the outcome when population is large but finite. The proposed research helps determine when the limit outcome converges to the prediction of the replicator dynamic as the population size grows. This result is then applied to the study of the evolutionary stability of cooperation when agents can migrate from one society to another. The focus is on when evolutionary forces will lead to "closed" societies that are distrustful of outsiders, and when in contrast societies will be "open."Broader Impacts: (A) Ideas from behavioral economics are now current in law schools and law reviews, leading science journals, and the popular press. However, the first generation of behavioral models has focused on special-purpose assumptions to fit specific facts, and it is now time to develop more systematic behavioral theories that explain many anomalies with the same, preferably few, departures from the standard model. The work in part A of the project contributes to that agenda.(B) The concept of an equilibrium of a game is used in many fields, including political science, sociology, computer science, biology, and psychology. Hence the project's study of how equilibrium can arise from non-equilibrium learning has a substantial impact outside of economics. Developing models of evolution in finite populations is very important for mathematical biology, and has begun to attract the attention of physicists. The particular question of the evolution of cooperation should be of interest to political scientists, sociologists, and biologists as well as to economists.