Total factor waste gas treatment efficiency of China’s iron and steel enterprises and its influencing factors: An empirical analysis based on the four-stage SBM-DEA model

Taking the four-stage SBM-DEA as the theoretical tool, this paper evaluates the total factor waste gas treatment efficiency (TFWGTE) of 65 Chinese iron and steel enterprises (CISEs) from 2005 to 2014. Then, after the influences of external environmental factors and statistical noise are eliminated, TFWGTE is decomposed into total factor waste gas managerial efficiency (TFWGME) and total factor waste gas environmental efficiency (TFWGEE), and the differences between TEWGTE, TEWGME and TEWGEE are systematically analysed from regional and enterprise perspectives. The results reveal that: (1) TFWGTE and TFWGEE showed an upward trend from 2005 to 2014, whereas TFWGME showed a downward trend from 2005 to 2014. The elimination of external environmental factors had provincial specific effects on TFWGTE; (2) By comparing the dynamic trends of TFWGTE in eastern, central and western regions, it is found that there are differences among different regions, which indicates that the external environmental factors in the region have an impact on TFWGTE; (3) In 4 provinces, TFWGME increased compared with TFWGTE, while in 23 provinces, TEWGME decreased compared with TFWGTE; (4) The Tobit regression results show that the command-and-control environmental regulation, environmental awareness and manufacturing process have significant effects on the input slacks of waste gas treatment, indicating that the strengthening of command-and-control environmental regulation, the improvement of environmental awareness, and the decline of the proportion of the short process can effectively reduce the input slacks of waste gas treatment.