The 1990 amendments to the Clean Air Act created a trading program in sulfur dioxide (SO2) emissions that has served as the seminal example of how an emissions trading program could be designed. Yet despite its success, the trading program was essentially brought to an end by a series of...

The use of cap-and-trade to regulate air pollution promises to achieve environmental goals at lower cost than traditional prescriptive approaches. Cap-and-trade has been applied to various air pollutants including sulfur dioxide, nitrogen oxides, and volatile organic compounds in the United...

Offsets lower the cost of cap-and-trade programs but must be considered imperfect if they cannot exclude “non-additional” emissions reductions or sequestration gains that would have occurred in their absence. Non-additionality can be addressed by requiring project-level additionality tests,...