Recent efforts to endogenize technological change in climate policy models demonstrate the importance of accounting for the opportunity cost of climate R&D investments. Because the social returns to R&D investments are typically higher than the social returns to other types of investment, any...

Instead of efficiently pricing greenhouse gases, policy makers have favored measures that implicitly or explicitly subsidize low carbon fuels. We simulate a transportation-sector cap & trade program (CAT) and three policies currently in use: ethanol subsidies, a renewable fuel standard (RFS),...