Risk Aversion and International Environmental Agreements

We introduce uncertainty and risk aversion to the study of international environmental agreements. We consider a simple model with identical agents and linear payoffs. We show that a stable treaty with positive action always exists. While uncertainty lowers the action of signatories, we find that it may increase participation. In addition, uncertainty may generate multiple equilibria. A treaty with low action and low participation may coexist with one with high action and high participation. Overall, and despite risk aversion, the impact of uncertainty on welfare may be positive. A reduction in uncertainty may hurt international cooperation.