Free Riding Reduces the Supply of Non-Excludable Goods
Designing Experiments to Understand Cooperation
Appendix: Experimental Instructions
A novel version of a Voluntary Contribution Mechanism game tests how player cooperation responds to changes in incentives, i.e., payoffs that depend on performance relative to different reference groups. Cooperation is greatest when players are competing against players in other four-person groups, intermediate when competition is diffused, and lowest when players compete in a zero-sum game within their own group.