Utilities in different states enact programs to save energy. Residential and commercial programs represent the most ubiquitous categories. But which of those programs provides the best return on investment (kilowatt-hours saved per dollar)? Under Commercial and Residential Savings , if we select Residential KWH per or Commercial KWH per , we see that savings are generally less for residential programs. If we select the third option, Ratio of Commercial to Residential KWH per , we see that the values are generally greater than 1.0, indicating that the commercial programs are providing more savings per dollar. What about efficiencies of scale? That is, perhaps one program tends to outshine the other depending on total energy saved or population size? The second pull-down menu, Explanatory Variable , has options for Megawatt Hours Saved and Population (Millions) . In both instances, I do not see a relationship between total energy saved or population size with any of the three savings categories. I would like to know what other factors may be driving inter-state differences in program savings.