We use the voluntary contribution mechanism to investigate whether smaller action sets lead to higher cooperation rates. We find that this is the case for groups of four players.

This paper presents experimental evidence from a simple three-person game showing that many individuals are willing to avenge third-party punishment in one-shot interactions. The threat of counter-punishment has a large negative effect on the willingness of third parties to punish selfish...

We perform a within-subject analysis of pro-social behavior in the public-good and gift-exchange game. We find that participants classified as cooperators in the public-good game tend to reciprocate higher wages in the gift-exchange game with higher levels of effort. Non-cooperators do not...