Carbon Prices, Preferences, and the Timing of Uncertainty. William Hogan, March 6, 2017, Paper, “$40 revised July 2015 Social Cost of CO2, from “Technical Update of the Social Cost of Carbon for Regulatory Impact Analysis Under Executive Order 12866.” (U. S. Government Interagency Working Group on Social Cost of Carbon, 2016) Based on 3% constant discount rate, and an average of 3 climate-economy models, including DICE.Link