Review of the network environmental efficiencies of listed petroleum enterprises in China

In this study, we create a set of network DEA models that can be used to divide efficiency scores into two subunits, thus providing more accurate results. This approach can help open the "black box" of efficiency measurement and help determine the advantages and disadvantages of various subunits in each decision-making unit. This study uses the newly presented models to examine changes in production and environmental efficiency among 20 listed petroleum enterprises in China. These examinations are conducted on a stage by stage basis using the enterprises' detailed production chains from the 20062011 period. Additionally, this study analyzes the input surpluses and output deficits from 2011. The results of using this approach (which looks to improve the input-output efficiency of enterprises) can be considered helpful in improving petroleum enterprises' technology and management efficiency. (C) 2014 Elsevier Ltd. All rights reserved.