In the use of peer group data to assess individual, typical or best practice performance, the effective detection of outliers is critical for achieving useful results, particularly for two-stage analyses. In the DEA-related literature, prior work on this issue has focused on the efficient...

Super efficiency models are useful for computing the Malmquist index and in methods for outlier detection, but conventional super-efficiency models may not have feasible solutions for some data sets. We show that a hyperbolic orientation eliminates the infeasibility problem, and permits...