Collaborative Research: A Subjective Model of Temporal Preferences

这个奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。这个项目开发和分析了一个新的经济理论模型。目标是在一个简单的模型中对个人偏好进行建模，在这个模型中，信息可能分两个阶段到达。我们引入了两类一般的陈述，一类是为那些希望不确定性及早解决的个人，另一类是为那些希望不确定性晚些解决的人。一般的表示可以被解释为好像在两个阶段之间由个人(或恶意的本性，取决于偏好是为了提前还是延迟解决不确定性)采取的动作(对于建模者来说是不可观察的)。众所周知，个人可能更愿意在较早的日期解决不确定性，以便能够以实现这种不确定性为其未来行动的条件。例如，一个人可能更愿意早点解决对未来收入的不确定性，这样她就可以平稳地进行一段时间的消费。假设一个人有可能在未来几年获得晋升并大幅加薪。如果她现在能够知道这一晋升决定的结果，那么即使她实际上要到以后才能收到增加的收入，她也可能选择通过暂时减少储蓄或增加债务来增加目前的消费。另一方面，如果她没有被告知晋升决定的结果，那么现在增加消费，她就有可能背负更大的债务，因此未来的消费水平可能会低于最佳水平。在这个例子中，改变解决不确定性的时机会增加个人根据不确定性的结果做出选择的能力，从而使个人受益。我们的表征结果可以被看作是这一观察结果的反面：当个体表现出对早期解决不确定性的偏好时，就好像她在两个阶段之间采取了(不可观察的)主观收益相关的行为。著名决策理论模型的主观版本被证明是我们一般表征的特例。因此，这项研究为各种现有模型创建了一个统一的框架。它提高了对这些模型主观版本的独特性程度的理解，并允许对解决不确定性的时间选择有丰富的偏好。了解唯一性属性允许我们明确地将表示的参数与选择行为联系在一起，使表示服从比较静力学和其他应用。在将这些模型应用于宏观经济学和金融经济学时，理解和区分对解决不确定性时机的丰富偏好类别是重要的，在宏观经济学和金融经济学中，对不确定性解决时机的偏好更简单的模型已经被证明相当有用。这项研究具有更广泛的影响；该项目开发的框架将用于将行为经济学的最新见解纳入金融经济学和决策科学。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project develops and analyzes a new model in economic theory. The goal is to model individual preferences in a simple model where information may arrive in two stages. We introduce two general classes of representations, one for individuals who prefer the uncertainty to resolve early and another one for those who prefer the uncertainty to resolve late. The general representations can be interpreted as if an action (unobservable to the modeler) is taken by the individual (or by the malevolent nature, depending on whether the preference is for early or late resolution of uncertainty) between the two periods. It is well known that an individual may prefer to have uncertainty resolve at an earlier date in order to be able to condition her future actions on the realization of this uncertainty. For example, an individual may prefer to have uncertainty about her future income resolve earlier so that she can smooth her consumption across time. Suppose an individual has the possibility of receiving a promotion with a substantial salary increase several years into the future. If she is able to learn the outcome of that promotion decision now, then even if she will not actually receive the increased income until a later date, she may choose to increase her current consumption by temporarily decreasing her savings or increasing her debt. On the other hand, if she is not told the outcome of the promotion decision, then by increasing her consumption now, she risks having larger debt and hence suboptimally lowconsumption in the future. In this example, changing the timing of the resolution of uncertainty benefits the individual by increasing her ability to condition her choices on the outcome of that uncertainty. Our representation result can be seen as a converse of this observation: Whenever the individual exhibits a preference for early resolution of uncertainty, it is as if she takes a (unobservable) subjective payoff-relevant action between the two periods.Subjective versions of well-known decision theoretic models are shown to be special cases of our general representations. Therefore, this research creates a unifying framework for a variety of existing models. It improves the understanding of the extent of uniqueness in the subjective versions of these models and allows for a rich class of preferences for timing of resolution of uncertainty. Understanding the uniqueness properties allows us to unambiguously tie the parameters of our representation to choice behavior, making the representations amenable to comparative statics and other applications. Understanding and distinguishing between a rich class of preferences for timing of resolution of uncertainty is important in applying these models to macroeconomics and financial economics, where even simpler models of preference for timing of resolution of uncertainty have already proved quite useful.This research has broader impact; the framework developed by this project will be used to incorporate recent insights from behavioral economics into financial economics and decision science.