Cap-and-Trade: The Evolution of an Economic Idea

Over the past three decades or so, emissions trading has evolved from an idea that was little more than an academic curiosity to its current role as the centerpiece of the U.S. program to control acid rain and international programs to control greenhouse gases. This essay identifies some of the key milestones of this evolution, describes how that evolution was shaped by economic analysis, elicits some of the lessons about the design and effectiveness of emissions trading that have emerged from analysis of that evolution, and points out a few of the barriers that lie in the path of achieving a truly global carbon market.