[1] Columbia Univ, Columbia Global Policy Initiat, New York, NY 10027 USA
[2] Columbia Univ, New York, NY 10027 USA
[3] Carnegie Council Eth, New York, NY USA
[4] US Council Econ, Washington, DC USA
[5] World Bank, Washington, DC USA
[6] Univ Cambridge, Cambridge CB2 1TN, England
[7] Univ Oxford All Souls Coll, Oxford OX1 4AL, England
[8] MIT, Cambridge, MA 02139 USA
[9] Yale Univ, New Haven, CT 06520 USA
[10] Stanford, Stanford, CA USA
[11] Princeton, Princeton, NJ USA