The Economics of Self Control, and the Evolution of Equilibrium

智力价值：A部分)在之前的工作中，Levine和Fudenberg发展了一个冲动控制的“双自我”模型，并认为它提供了一种易于处理和节俭的方式来解释通常被用来激励准双曲偏好的事实，例如在金钱奖励选择和过度拖延方面的时间不一致。该项目将同样的模型应用于一系列新的应用，包括阿莱悖论，该悖论依赖于决策理论的“独立公理”正以双重自我模型预测的方式被违反。该项目还开发了区分标准偏好、双重自我偏好和准双曲线偏好的预测和实证测试。B)本项目这一部分的起点是，博弈中的均衡最好被理解为学习、模仿或进化的非均衡动态过程的长期结果。该项目侧重于两个具有明显不同适用领域和结论的进程。研究的第一个过程是代理人的理性学习，他们利用对过去比赛的观察来形成他们对对手未来可能如何比赛的信念。以前的工作依赖于简化的假设，即给定玩家角色中的所有代理都会收到相同的信号并具有相同的信念；项目确定这种简化何时有效。研究的第二个过程是有限理性模仿或“混杂”，其中代理倾向于复制当前收益较高的策略。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“复制者动态”，但这个模型的长期结果并不总是一个很好的近似结果，当种群大但有限的时候。拟议的研究有助于确定随着种群规模的增长，极限结果何时收敛于复制因子动态的预测。然后将这一结果应用于研究当代理人可以从一个社会迁移到另一个社会时合作的进化稳定性。人们关注的焦点是进化力量何时会导致不信任外来者的“封闭”社会，以及何时社会会变得“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学评论、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符合特定事实的特殊目的假设，现在是时候开发更系统的行为理论，解释许多与标准模型相同的、最好是较少偏离的异常现象。(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，该项目对均衡如何从非均衡学习中产生的研究在经济学之外具有重大影响。发展有限种群的进化模型对于数学生物学来说是非常重要的，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.