By using data collected from the NCR depots (Container Corporation of India, 2010), we review the eco-DEA models discussed in the previous section.
Table 1 gives the data of the 16 DMUs, with three inputs and two outputs, one of which is undesirable (emissions). DEAP 2.1 is used to run the models. The study assumes variable returns to scale.
Finding 1:
The existing approaches tend to increase efficiency scores.
According to Table 2, when method 1 is compared with other approaches, the efficiency scores are fairly similar. In general, the number of efficient DMUs and the mean efficiency score under methods 2, 3 and 4 are similar. However, there is a small increase in the efficiency ratios.