Replication Data for Cooperative communities in the international system: Networked cooperation of homophilous states

A central puzzle of international relations research is understanding how groups of cooperative states form. While in theory cooperative groups of states can be made up of states with diverse domestic organizations, in practice, groups of cooperative states tend to have similar domestic characteristics. In this regard, the current state of knowledge on international cooperation is lacking. I fill this research gap by analyzing how network relations simultaneously affect the domestic organization of and conflict among states. Specifically, I argue that frequent interactions and dynamic network formation, help states signal their preferences, interests, and capabilities. This information helps spread the political institutions of more powerful states, while alleviating information and coordination problems within groups of states. Over time, this creates cooperative communities, or politically homophilous groups of states that are more internally cooperative. When these processes are jointly considered, shared institutional characteristics have a null effect on interstate conflict.