Common-Value Public Goods and Informational Social Dilemmas

We experimentally examine private information and communication in a public goods environment with uncertain returns. We consider a common-value public goods game in which the return to contribution is either high or low. Before contributing, three players observe private signals correlated with the return and send cheap talk messages to one another. There are social gains from truthfulness, but a private incentive to exaggerate. We compare treatments with and without cheap talk, finding that communication is largely truthful and increases efficiency. In further treatments, we increase the incentive to exaggerate and find reduced truthfulness and smaller gains from communication.