Focusing on residential electricity demand, researchers conducted the first-ever study that using micro-data on households. The dataset consists of more than 7 million observations on monthly billing data for nearly all households in southern Indiana over a three year time frame.

The main finding is that DST increases residential electricity demand ranging from 1 to 4 percent. The study shows some evidence of electricity savings during the spring, but the effect lessens near the end of the Daylight Savings Time period in the fall. These findings are consistent with simulation results that point to a tradeoff between reducing demand for lighting and increasing demand for heating and cooling.

Based on the dates of DST practice before the 2007 extensions, the research estimates a cost of increased electricity bills to Indiana households of $8.6 million per year. Estimates of social costs of increased pollution emissions ranged from $1.6 to $5.3 million per year.