US-China Joint Declaration at the 2021 Glasgow Climate Summit

Evaluating a Global Climate Accord's Effectiveness

Two countries face a strategic choice regarding emissions policy. Initially, both have a strong incentive not to restrict emissions, leading to a poor environmental outcome for both. A new international agreement is proposed that provides a 'cooperation bonus' to any country that chooses to restrict emissions. The new payoffs are represented in the matrix below (Country A's payoff, Country B's payoff).

Based on this new payoff structure, why is the agreement considered successful in promoting mutual cooperation?

Designing an Effective Climate Treaty

Evaluating Climate Policy Strategies

Two countries are in a strategic situation where both are incentivized to continue emitting pollutants ('Don't Restrict') rather than curbing them ('Restrict'), even though mutual restriction would be better for both. Match each policy intervention below with its primary effect on the strategic incentives, aimed at making mutual restriction a stable outcome.

For a global climate agreement to be successful in the long term, it must rely primarily on the goodwill and altruism of participating nations to overcome their individual self-interest.

For a global climate agreement to successfully overcome the social dilemma of pollution, the payoffs for participating nations must be restructured. The goal is to ensure that the outcome where all countries restrict emissions becomes a stable ______, a state from which no single nation can improve its own outcome by unilaterally changing its decision.

Imagine two countries are in a strategic situation where it is individually rational for each to pollute, leading to a poor environmental outcome for both. Arrange the following steps in the logical order a policymaker would follow to design an international agreement that successfully makes mutual emission restriction a stable, self-enforcing outcome.

Two large economies are deciding whether to restrict their carbon emissions. The payoffs for their decisions are represented in the matrix below, where the first number in each pair is the payoff for Economy A and the second is for Economy B. The current strategic situation results in a suboptimal outcome where neither economy restricts emissions because there is a strong incentive to be a 'free-rider'.

Which of the following policy changes would be most effective in making mutual restriction ('Restrict', 'Restrict') a stable equilibrium from which neither economy has a self-interested incentive to unilaterally deviate?

Altering Payoffs to Make Mutual Restriction a Stable Equilibrium

Strategic Flaw in a Climate Agreement

Altering Payoffs to Make Cooperation a Stable Equilibrium

Evaluating Climate Policy Strategies