On network efficiency comparisons: Electricity distribution

Short-run efficiency comparisons for electricity distribution networks, a matter of their operating costs, require a clear concept of the scale of what they do. A measure is proposed. Long-run comparisons require an estimate of the input of capital services which avoids the circularity of concepts which depend upon the productivity that is to be compared. The extremely stringent conditions for using a perpetual inventory approach are set out. A measure of capacity is also proposed, not energy (which is a throughput and not an output).