Experimental evidence from public good games with punishment suggests that punishment works when subjects assign it fairly by sanctioning non-cooperators. This paper reports an experiment in which punishment is assigned unfairly in the sense that it is not linked to individual behaviour and is melted out to all group members (irrespective of their prior behaviour). We test whether unfair punishment generates different contribution and punishment behaviour relative to the standard punishment game. Our findings suggest different dynamics of average contributions in the presence of unfair punishment relative to the standard punishment game. Contribution levels are significantly different only when subjects have obtained experience from both games. We also find that, although the assignment of punishment is unaffected after the experience of an environment with unfair punishment, a history of unfair punishment makes a difference regarding reactions to alleviation, reward and punishment received.
