One factor that makes climate change mitigation difficult is its long-term horizon. Here we frame this social dilemma as a "public bad" that captures the key features of the problem and in particular its dynamic externality. In a theory-based experimental platform, we compare static vs. dynamic versions of the dilemma in order to assess how the dynamic aspect of this game affects the ability of countries to cooperate. While the average level of cooperation is similar, the a dynamic externality presents a strong, declining trend of cooperation.

Keywords: Experiment; Climate change; Cooperation; Inequality