On regular and parametric data envelopment analysis

We give a generic regularity condition under which each weakly efficient decision making unit in the CCR model of data envelopment analysis is also CCR-efficient. Then we interpret the problem of finding maximal parameters which preserve efficiency of CCR-efficient DMUs under directional perturbations as a general semi-infinite optimization problem and use a recently suggested numerical method for this problem class to calculate maximal directionally efficient DMUs. As a practical example we investigate the efficiency of Croatian banks under additive perturbations. Copyright Springer-Verlag 2004