We present a new and simple mechanism for repeated public good environments. In the Conditional Contribution Mechanism (CCM), agents send two message of the form, "I am willing to contribute x units to the public good if in total y units are contributed." This mechanism offers agents risk-free...

We augment the standard cartel formation game from non-cooperative coalition theory, often applied in the context of international environmental agreements on climate change, with the possibility that singletons support coalition formation without becoming coalition members themselves. Rather,...