The use of virtual weights restrictions in data envelopment analysis

摘要: The consequences of the use of absolute weights restrictions on the efficiency score and targets of a DEA model have been explored elsewhere, the same was not true for the use of restrictions on the virtuals. In this paper, a reflection on the uses of virtual weights restrictions is presented. The reasons for using virtual weights restrictions instead of absolute weights restrictions are explained. Following a critique of Wong and Beasley’s proposed method for constraining the virtuals in DEA, a new classification scheme for virtual weights restrictions is presented, which brings the concept of assurance regions into virtual weights restrictions. It is shown that the use of simple virtual restrictions and virtual assurance regions are preferable to the use of the more generally advocated proportional virtual weights restrictions. In recognition of levels of decision making at the unit, and external to the unit, the use of the terms unit of …