On April 25, KPMG International released an index ranking 21 countries on their efforts to encourage sustainable corporate activity through the tax code. The U.S. is ranked number one, and KPMG cited energy efficiency incentives at the federal level, green building tax incentives, and the renewable energy production tax credit. The index reviews incentives and penalties on a variety of topics ranging from energy efficiency to carbon emissions. Following the U.S. are Japan, the U.K., France, South Korea, and China in the top six positions.