2026-07-09http://hdl.handle.net/123456789/539615Super efficiency evaluations are introduced along the lines of the potential improvements approach in Bogetoft and Hougaard (1999). Both a reference selection and a related super efficiency index is defined. The new (potential slack) super efficiency index is compared to a Farrell-based super efficiency index (as in Andersen and Petersen 1993) with respect to convex envelopment technologies.Text