1. Richard Schmalensee is the Howard W. Johnson Professor of Management Emeritus, Professor of Economics Emeritus, and Dean Emeritus, Massachusetts Institute of Technology Sloan School of Management, Cambridge, Massachusetts.
2. Robert N. Stavins is the A. J. Meyer Professor of Energy and Economic Development, Harvard Kennedy School, Cambridge, Massachusetts; University Fellow, Resources for the Future, Washington, DC; and Research Associate, National Bureau of Economic Research, Cambridge, Massachusetts.