CO2 emission performance evaluation of Chinese port enterprises: A modified meta-frontier non-radial directional distance function approach

The rapid development of China's port industry has led to serious CO2 emission problems. In this study, using the panel data of 16 port enterprises in China during 2013-2018, we first classified port enterprises into two groups based on the criterion of size and complexity. Then, we use a modified non-radial directional distance function in the meta-frontier framework to evaluate the port CEP and its dynamic changes as well as driving forces. The results show that the CEP of the whole is poor over the sample period on the basis of meta-frontier. Both groups performed well in CEP with respect to their specific group frontiers. Driving forces of the growth of CEP differ among port groups and individual port. Additionally, the effect of environmental regulation on CEP is positive, while the effect of openness on the growth of CEP is negative.