Abstract
Undesirable outputs are usually produced along with desirable outputs. However, it is difficult to evaluate undesirable-output-considered efficiency and realize the complete sequencing of efficiency levels with traditional super-efficiency data envelopment analysis (DEA) models. In this paper, a kind of super-efficiency DEA model considering both desirable and undesirable outputs will be proposed based on the classical slack-based measure (SBM) environmental efficiency evaluation model. And the super-efficiency values will be calculated to realize the complete ranking of all decision making units (DMUs). After that, “projection” of DMUs will be used to provide benchmark for evaluated DMUs. Then, our approach is applied to an practical example of 42 thermoelectric enterprises in China. We find that there are many good properties of this new model compared with traditional models, by which not only complete sequencing of those thermoelectric enterprises can be realized but also significant differences among them can be revealed. The efficiencies of DEA inefficient enterprises are comparatively low, that is to say, these enterprises should improve their environmental efficiency levels and cleaner production largely to be efficient.