Economists often regard broad-based carbon pricing (whether in the form of a carbon tax or cap and trade) as the most efficient policy to reduce carbon dioxide emissions. Relative to a narrower policy that exempts some emissions sources, a broader policy is often favored because it can exploit...

China's recently launched CO2 emissions trading system, already the world's largest, aims to contribute importantly toward global reductions in greenhouse gas emissions. The system, a tradable performance standard (TPS), differs importantly from cap and trade (C&T), the principal emissions...