In a Nash equilibrium of voluntary participation games in international environmental agreements, the optimal surplus sharing rules, proposed by Eyckmans and Finus (2004) and Weikard (2009), incentivize more countries to participate in the agreements. We examine how robust this desirability of...

We examine how the voluntary participation decision in international environmental negotiations affects negotiation outcomes when every country is a federation. Each country consists of two autonomous regions: one is a polluter region and the other is a nonpolluter region. In the model, each...