Measuring China's industrial energy efficiency, both DEA and directional distance function approach at the provincial level

Evaluation of the provincial industrial energy efficiency has recently attracted an increasing interest. A lot of previous researches were conducive to the evaluation of regional energy efficiency employing various types of DEA model. Using data envelopment analysis (DEA) and directional distance function (DDF) approach, this article constructs two models based on the total factor framework and analyses the energy efficiency and the energy-saving potential in China during 2008-2012; meanwhile, it combines partial factor energy efficiency and the total factor energy efficiency based on two models, and introduces the target energy intensity indicator measures the energy intensity efficiency of each province. The empirical study results show that in the target course of the study, east China is more effective than west and central China, thanks to the higher energy saving and emissions reduction in east China. The energy efficiency differences are significant among areas, and energy-saving and output expansions also have a great improvement potential. Thus, changing economic growth pattern from 'extensive type to 'intensive type' is still a strategic priority for a very long time in China.