An Experimental Comparison of the Fairness and Learning Hypotheses

长期以来，公共产品的提供一直是微观经济学的一个重要问题。粗略地说，公共物品是任何可以同时使大量个人受益的物品，并且很难排除个人消费。公共产品的例子可能包括公园、清洁的空气或国防。提供公共产品的核心困难是搭便车问题；如果不可能将个人排除在公共产品的利益之外，那么如果其他人愿意提供公共产品，他/她就没有什么动力为公共产品的提供付费。理论家们提出了许多旨在缓解搭便车问题的机制。虽然所有这些机制在理论上都是有效的，但它们并不比它们对个人行为的基本假设更好。实验经济学通过为公共物品问题中的行为提供受控的经验证据，在公共物品研究中发挥了不可估量的作用。众所周知，公共产品和讨价还价实验产生的结果与标准的微观经济学理论相悖。两类理论--基于人际效用函数(‘公平’)或基于有限理性学习模型--被提出来解释这些结果。既没有解释所有的实验数据，也没有明显优于另一种。我们的实验探索了公共产品博弈中主体的行为是用公平假说、学习假说还是结合它们的混合模型来最好地解释。我们的实验是基于van de Krat，Orbell和Dawes提出的最小贡献集公共产品博弈。我们考虑三种基本的变化。一种是将没有经验的玩家推向子博弈的完美均衡，一种是将玩家推向公平均衡，另一种是将这两种结果中的任何一种都设计为合理的结果。通过让受试者在玩第三个游戏之前参与前两个游戏中的一个，我们控制了受试者进入第三个游戏的先前经验。考察具有不同先前经验的课程之间受试者行为的差异，使我们能够澄清学习和公平在产生受试者行为方面的作用。

The provision of public goods has long been a important problem in microeconomics. Roughly, a public good is any item which can benefit a large number of individuals simultaneously and which it is difficult to exclude individuals from consuming. Examples of public goods might include public parks, clean air, or national defense. The central difficulty with the provision of public goods is the free rider problem; if it is impossible to exclude an individual from the benefits of a public good, he/she has little incentive to pay for provision of the public good if others are willing to provide it. Theorists have proposed a number of mechanisms designed to alleviate the free rider problem. While all of these mechanisms work in theory, they are no better than their underlying assumptions about individuals' behavior. Experimental economics has played an invaluable role in the study of public goods by providing controlled empirical evidence on behavior in public goods problems. It is well known that public goods and bargaining experiments yield results which are at odds with standard microeconomic theory. Two classes of theory, based on interpersonal utility functions (`fairness`) or on boundedly rational learning models, have been proposed to explain these results. Neither explains all of the experimental data or clearly outperforms the other. Our experiments explore whether subjects' behavior in a public goods game can best be explained by the fairness hypothesis, the learning hypothesis, or a hybrid model which combines them. Our experiments are based on the Minimum Contributing Set public goods game developed by van de Kragt, Orbell, and Dawes. We consider three basic variations. One is designed to push inexperienced players towards the subgame perfect equilibrium, one is designed to push players toward the `fair` equilibrium, and one is designed with either outcome as a plausible outcome. By having subjects participate in one of the first two games before playing the third, we control the subjects' prior experience entering the third game. Examining differences in subject behavior between sessions with differing prior experience allows us to clarify the roles of learning and fairness in generating subjects' behavior.