Reciprocity can be a powerful motivation for human behaviour. Scholars argue that it is relevant in the context of private provision of public goods. We examine whether reciprocity can resolve the associated coordination problem. The interaction of reciprocity with cost-sharing is critical....

We develop, and experimentally test, models of informal agreements. Agents are assumed to be honest but suffer costs of overcoming temptations. We extend two classical bargaining solutions -- split-the-difference and deal-me-out -- to this informal agreement setting. For each solution there are...

We develop, and experimentally test, a behavioral model of deal- making which includes binding contracts and informal agreements as distinct but related special cases. The key assumptions: people are mostly honest; they suffer costs of overcoming temptation to renege; and they tend to split gains...