Intragroup competition in public good games: The role of relative performance incentives and risk attitudes

We analyze a public good game (PGG) with intragroup competition in which, generally but not always, the dominant strategy is to not contribute; therefore, free riding is the unique Nash equilibrium, not achieving Pareto efficiency. We propose a PGG setup where subjects' contributions are rewarded with different individual returns following a rank-order voluntary contribution mechanism. It is found that the resulting competition for a better return significantly increases contributions. This effect is sensitive to the salience of return differences rewarding higher contributions. Furthermore, the positive effect of return differences on contribution levels depends on an individual's return-to-risk sensitivity as elicited through an independent risk elicitation task.