The conditional contribution mechanism for repeated public goods – The general case

We present a new and simple mechanism for repeated public good environments. In the Conditional Contribution Mechanism (CCM), agents send two messages of form, “I am willing to contribute x units if in total y are contributed.” This offers risk-free strategies, which we call unexploitable. Our main theorem states that all outcomes CCM will eventually be Pareto efficient choose unexploitable better responses. conduct laboratory experiment investigate whether observed behavior is consistent with this prediction. complete information case find indeed almost 80% optimal. Furthermore, comparison Voluntary Mechanism, leads significantly higher contribution rates. Even under incomplete information, contributions fairly high do not deteriorate over time, although surprisingly VCM does equally well case. Theoretically, allowing helps them ensure status-quo at same time offer levels. further treatment, where allow only one message, consistently lower than early periods but similar later periods.