Ex Interim Voting in Public Good Provision

We report the results of an experimental study that compares voting mechanismsin the provision of public goods. Subjects can freely decide how much they want tocontribute. Whether the public good is finally provided is decided by a referendumunder full information about all contributions. If provision is rejected, contributionsare reduced by a fee and reimbursed. We compare unanimity with majority votingand both to the baseline of cheap talk. Contributions are highest under unanimity.Yet, results concerning overall efficiency are mixed. When provision occurs, onlyunanimity enhances e±ciency. Overall, however, unanimity leads to too manyrejections.