Informational Benefits of International Treaties

International treaties allow a minister in one country to learn about the beliefs held by a minister in another country, so allowing each to make better decisions. When the net benefits of environmental policy are uncertain, a country which participates in negotiating an environmental treaty, or which supports strong environmental action, thereby provides information to another country that such action can be worthwhile. This dimension of international environmental agreements helps explain why countries negotiate treaties, why these treaties often implement the Nash non-cooperative equilibrium, why agreement to a treaty by a country deemed not particularly favorable to it can strengthen environmental action, and why treaties may invoke a minimum participation clause. The informational mechanism we discuss holds even if physical spillovers are absent, and even if monitoring and enforcement are infeasible. Our approach can explain additional phenomena: how requirements for approval by several bodies within a country can increase support for a policy, and why simultaneous action can lead to better outcomes than sequential action.