Trends in energy efficiency: State-level comparisons

The results of studies designed to isolate and quantify energy achievements may be sensitive to the approach used to aggregate different types of energy resources. Ifa Btu measure of residential per capita energy consumption is employed, energy efficiency gains are suggested for key U.S. states. However, ifa Divisia index approach is followed (and different energy resources are aggregated according to their economic value), little gain in energy efficiency over the past 13 years is evident. lit the manufacturing sector, the positive energy efficiency gains for some regions suggested by simple Btu measures of total energy consumption appear to be greatly overstated. A decomposition of Divisia energy aggregates suggest much lower energy efficiency gains for various U.S. regions.