The Design of a Carbon Tax

We consider the design of a tax on greenhouse gas emissions for the United States. We consider three major issues: the tax rate (including the use of the revenues and rate changes over time), the optimal tax base, and international trade concerns. We show that a well-designed carbon tax can capture about 80% of U.S. emissions by taxing only a few thousand taxpayers, and almost 90% with a modest additional cost. We recommend full or partial delegation of rate setting authority to an agency to ensure that rates reflect current information about the costs of carbon emissions and abatement. Adjustments should be made to the income tax to ensure that a carbon tax is revenue neutral and distributionally neutral. Finally, we propose an origin-basis system for trade with countries that have an adequate carbon tax, and a system of border taxes for imports from countries without a carbon tax. We suggest a system that imposes presumptive border tax adjustments, but allows an individual firm to prove that a different rate should apply. The presumptive tax could be based on average emissions for production of the item by either the exporting country or the importing country.