Slack-adjusted efficiency measures and ranking of efficient units

In non-parametric methods many units are calculated as efficient. The article suggests a method for ranking efficient units, not by their efficiency but by importance as benchmarks for the inefficient units, in contrast to earlier suggestions in the literature which rank units high if they are specialized, However, the total potentials for improvement frequently remain unrevealed by calculating radial efficiency measures of the Farrell type only. The article therefore first develops efficiency measures that explicitly extend the radial measures to include slacks. The new measures are applied to a typical multidimensional small-sample data set for Norwegian employment offices.