A Correction on Data Envelopment Analysis for Environmental Assessment Using Methodological Comparison between Three Efficiency Measurement Models

This study introduces a revised data envelopment analysis (DEA) model to explore a new use of DEA for the environmental assessment in which outputs are classified into desirable (good) and undesirable (bad). Such an output separation is important in the DEA-based environmental assessment. We used a Range-Adjusted Measure (RAM) DEA model that is a kind of non-radial DEA model for combining the two performance measures, operational and environmental performance as an unified measure. Some of the previous studies that are recently published in this context proposed two alternative models of unification for DEA-based environmental assessment, too. Some drawbacks in their models reduce their usefulness. In fact, we revise their models in this study, and then we compare the three types of unification from methodological and mathematical perspectives of environmental assessment. We proposed a DEA based environmental method for evaluating a set of kinds of organizations. Some of the studies believe that for decreasing the amount of undesirable outputs, we should increase the amount of inputs. But the present work revealed that focusing on reducing the undesirable outputs to reach goal is very important than its increase or decrease in the amount of inputs.