1. Stanford University, Stanford, CA 94305, USA.
2. University of Maryland, College Park, MD 20742, USA.
3. Resources for the Future, Washington, DC 20036, USA.
4. Toulouse School of Economics, 31000 Toulouse, France.
5. London School of Economics, London WC2A 2AE, UK.
6. Columbia Business School, New York, NY 10027, USA.
7. Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
8. National Bureau of Economic Research, Cambridge, MA 02138, USA.
9. Cowles Foundation, Yale University, New Haven, CT 06511, USA.
10. Sloan School of Management, Massachusetts Institute of Technology, Newton, MA 02159, USA.
11. Sanford School of Public Policy, Duke University, Durham, NC 27708, USA.
12. University of Arizona, Tucson, AZ 85721, USA.
13. University of Gothenburg, SE-405 30 Gothenburg, Sweden.
14. Univeristy of Sussex, Sussex BN1 9SL, UK.
15. Institute for Environmental Studies and Department of Economics, Vrije Universiteit, 1081 HV Amsterdam, Netherlands.
16. Harvard University, Cambridge, MA 02138, USA.