Carpenter and Matthews (2009) examine the cooperation norms determining people's punishment behavior in a social-dilemma game. Their findings are striking: absolute norms outperform the relative norms commonly regarded as the determinants of punishment. Using multiple punishment stages and...

We study the effect of voting when insiders’ public goods provision may affect passive outsiders. Without voting insiders’ contributions do not differ, regardless of whether outsiders are positively or negatively affected or even unaffected. Voting on the recommended contribution level...

Public good provision is often local and also affects bystanders. Is provision harder if contributions harm bystanders, and is provision easier if outsiders gain a windfall profit? In an experiment we observe that both positive and negative externalities reduce provision levels whenever actors...