Measuring the Energy Savings from Home Improvement Investments: Evidence from Monthly Billing Data
利用独特数据集，发现阁楼保温的实际回报率（中位数9.7%）与CAPM隐含折现率几乎一致，表明能源悖论可能不如以往认为的那么显著。
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. © 1999 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology