This paper provides a comprehensive theoretical model of the political decision making process. Therein two ideologically different political parties compete for power. Their primary instrument in this competition are programmatic concessions in favor of voters and interest groups. As any...

Cities increasingly address climate change, e.g. by pledging city-level emission reduction targets. This is puzzling for the provision of a global public good: what are city governments' reasons for doing so, and do pledges actually translate into emission reductions? Empirical studies have...

We develop a model that combines competitive exchange of private commodities across endogenously formed groups with public good provision and global collective decisions. There is a tension between local and global collective decisions. In particular, we show that group formation and collective...