Numerous laboratory experiments show that workers reciprocate to high wages with high effort, when there is perfect information on the surplus created. Recent field experiments, however, suggest that trust and reciprocity may be lower or absent when the information is incomplete. We report a...

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...