A comment on multi-stage DEA methodology

Coelli (Oper. Res. Lett. 23 (1998) 143) introduced a multi-stage (MS-) DEA methodology that represents an interesting alternative for the treatment of slacks remaining after proportional correction in inputs or outputs. By solving a sequence of radial models, one thus arrives at the identification of "more representative efficient points" (in terms of similar input/output mixes). We show that "most representative efficient points" can be found using a direct approach and may differ from those obtained by MS-DEA. Nevertheless, MS-DEA remains very attractive in view of its economic (intrinsic price) legitimation. (C) 2001 Elsevier Science B.V. All rights reserved.