Using a simple decision-theoretic approach, we formalize how agents with different kinds of intrinsic motivations react to the introduction of monetary incentives. We contend that empirical results supporting the existence of a crowding-out effect in various contexts hide a more complex reality....

Providing public goods is hard, because providers are best off free-riding. Is it even harder if one group's public good is a public bad for another group or, conversely, gives the latter a windfall profit? We experimentally study public goods provision embedded in a social context and find that...

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...