Carbon taxes, which impose a price per ton of CO2 emitted, have typically been favored by economists. They are a classic way of internalizing an externality by forcing emitters to pay for the social cost of their carbon emissions, and a tax in such an instance is the classic prescription from economic theory. Currently, carbon taxes exist in many jurisdictions, though they vary in scope: Japan’s carbon tax is at the lower end, less than USD10 per ton, whereas Sweden’s is currently the world’s highest, at around USD125 per ton.