We aim to understand the role and evolution of beliefs in the indefinitely repeated prisoner’s dilemma (IRPD). To do so, we elicit beliefs about the supergame strategies chosen by others. We find that heterogeneity in beliefs and changes in beliefs with experience are central to understanding...

In an experiment on the repeated prisoner s dilemma where intended actions are implemented with noise, Fudenberg et al. (2012) observe that non-equilibrium strategies of the "tit-for-tat" family are largely adopted. Furthermore, they do not find support for risk dominance of TFT as a determinant...

Intelligence affects social outcomes of groups. A systematic study of the link is provided in an experiment where two groups of subjects with different levels of intelligence, but otherwise similar, play a repeated prisoner's dilemma. The initial cooperation rates are similar, it increases in...

We use a novel experimental design to disentangle strategically- and non-strategically-motivated cooperation. By using contingent responses in a repeated sequential prisoners' dilemma with a known probabilistic end, we differentiate end-game behavior from continuation behavior within individuals...

The prisoner's dilemma (PD) is arguably the most important model of social dilemmas, but our knowledge about how a PD's material payoff structure affects cooperation is incomplete. In this paper we investigate the effect of variation in material payoffs on cooperation, focussing on one-shot PD...

We report the results of a field experiment with bicycle messengers in Switzerland and the United States. Messenger work is individualized enough that firms can choose to condition pay on it, but significant externalities in messenger behavior nonetheless give their on-the-job interactions the...

Using a negatively framed public good game, we study the cooperative behavior of individuals who reintegrate their group after being excluded by their peers. We manipulate the length of exclusion and whether this length is imposed exogenously or results from a vote. We show that people are...

In social dilemmas, leading a team by making heroic efforts may prove costly, especially if the followers are not adequately motivated to make similar sacrifices. Attempting to understand what motivates these seemingly selfless individuals to lead, we report the results of a two-stage public...

This paper introduces new experimental designs to enrich understanding of conditional cooperation and punishment in public good games. The key to these methods is to elicit complete contribution or punishment profiles using the strategy method. It is found that the selfish bias in conditional...