Gilbert E. Metcalf is Professor of Economics at Tufts University, Massachusetts, and a Research Associate at the National Bureau of Economic Research. He is also a Research Associate in the Joint Program on the Science and Policy of Global Change at MIT and currently a Visiting Professor in the Department of Economics at MIT where he teaches a class on the economics of energy markets. Professor Metcalf recently served as a member of the US National Academy of Sciences' Committee on Health, Environmental, and Other External Costs and Benefits of Energy Production and Consumption, and the peer-r...