The climate crisis is the most important long-term challenge facing policymakers around the world. Addressing it will require deep economic transformations within and across national borders, and a mix of ambition and pragmatism about what nations’ individual political and legal constraints...

The increase in carbon dioxide emissions by some countries in reaction to an emission reduction by countries with climate policy (carbon leakage) is seen as a serious threat to unilateral climate policy. Using a two-country model where only one of the countries enforces an exogenous cap on...