Elke Renner

We use a limited information environment to assess the role of confusion in the repeated voluntary contributions game. A comparison with play in a standard version of the game suggests, that the common claim that decision errors due to confused subjects biases estimates of cooperation upwards, is not necessarily correct. Furthermore, we find that simple learning cannot generate the kind of contribution dynamics commonly attributed to the existence of conditional cooperators. We conclude that cooperative behavior and its decay observed in public goods games is not a pure artefact of confusion and learning.

We examine the characteristics of effective leaders in a simple leader‐follower voluntary contributions game. We focus on two factors: the individual's cooperativeness and the individual's beliefs about the cooperativeness of others. We find that groups perform best when led by those who are cooperatively inclined. Partly, this reflects a false consensus effect: cooperative leaders are more optimistic than noncooperators about the cooperativeness of followers. However, cooperative leaders contribute more than noncooperative leaders even after controlling for optimism. We conclude that differing leader contributions by differing types of leader in large part reflects social motivations.(JELA13, C92, D03)

Belief elicitation is an important methodological issue for experimental economists. There are two generic questions: 1) Do incentives increase belief accuracy? 2) Are there interaction effects of beliefs and decisions? We investigate these questions in the case of finitely repeated public goods experiments. We find that belief accuracy is significantly higher when beliefs are incentivized. The relationship between contributions and beliefs is slightly steeper under incentives. However, we find that incentivized beliefs tend to lead to higher contribution levels than either non-incentivized beliefs or no beliefs at all. We discuss the implications of our results for the design of public good experiments.

Experiments have shown that punishment enhances socially beneficial cooperation but that the costs of punishment outweigh the gains from cooperation. This challenges evolutionary models of altruistic cooperation and punishment, which predict that punishment will be beneficial. We compared 10- and 50-period cooperation experiments. With the longer time horizon, punishment is unambiguously beneficial.