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 transferable discharge permits as a water pollution control policy is rapidly increasing in the United States. Drawing on evidence from existing water quality trading programs, this paper provides a taxonomy of the forms that such markets take. Four main structures are identified:...