We evaluate the effect of a change in the energy code applied to buildings using residential billing data on electricity and natural gas, combined with data on observable characteristics of each residence. The study is based on comparisons between residences constructed just before and after an increase in the stringency of Florida's energy code in 2002. We find that the code change is associated with a decrease in the consumption of electricity by 4% and natural gas by 6%. We estimate average social and private payback periods that range between 3.5 and 6.4 years.

We take advantage of a natural experiment in the state of Indiana to estimate the effect of daylight saving time (DST) on residential electricity consumption. Our main finding is that, contrary to the policy's intent, DST increases electricity demand. The findings are consistent with simulation results that identify a trade-off between reducing demand for lighting and increasing demand for heating and cooling. We estimate a cost to Indiana households of $9 million per year in increased electricity bills. We also estimate social costs of increased pollution emissions between $1.7 to $5.5 million per year.