Tax expenditures are a major source of support for energy related to activities in the federal budget exceeding direct budget support for energy by a factor of nearly six. Focusing on the policy goals of reducing greenhouse gas emissions and petroleum consumption, I find these tax expenditures highly cost ineffective at best and counterproductive at worse. The tax credit for ethanol is an example of a cost ineffective subsidy. The cost of reducing CO2 emissions through this subsidy exceeded $1,700 per ton of CO2 avoided in 2006 and the cost of reducing oil consumption over $85 per barrel.

An important factor driving energy policy over the past two decades has been the “energy paradox,” the perception that consumers apply unreasonably high hurdle rates to energy-saving investments. We explore one possible explanation for this apparent puzzle: that realized returns fall short of the returns promised by engineers and product manufacturers. Using a unique data set, we find that the realized return to attic insulation is statistically significant, but the median estimate (9.7%) is almost identical to a discount rate for this investment implied by a CAPM analysis. We conclude that the case for the energy paradox is weaker than has previously been believed.