I examine a policy-making game among countries that must choose both a policy instrument (e.g., a tax or a quota) and its intensity (i.e., the tax rate or the quota level) to price pollution. When countries price pollution non-cooperatively, they not only set the intensity inefficiently, they...

This paper examines leadership in relation to supplying a global public good. Both the Kyoto Protocol and the Paris Agreement encourage the developed countries to take a lead in reducing emissions. Does a country benefit from taking a lead? When does leadership improve global welfare? The answer...

Finland introduced the planet’s first carbon tax in 1990 to experiment with, to most economists, the best policy to reverse carbon emissions. I estimate the causal effect of taxing carbon on Finnish emissions using the Synthetic Control Approach (Abadie, 2021). The results suggest that taxing...