Abstract:

Global awareness on energy security and climate change has created much interest in assessing economywide energy efficiency.A number of previous studies have contributed to evaluate energy efficiency using different analytical techniques，among which data envelopment analysis (DEA) has recently received increasing attention.Most of DEArelated energy efficiency studies do not consider undesirable outputs,which may lead to biased energy efficiency values.In order to calculate the value of the energy efficiency accurately,non radial SBM(Slackbased measure) directional distance function was used to evaluate the energy efficiency of 29 provinces (except Tibet) in China from 1996 to 2010 under the constraint of environment. In this research,energy,labor,and capital were chosen as the three inputs,while GDP as the good output,SO2 emission as a substitute variable for environmental effects of energy utilization.The analysis indicated that the efficiency of energy utilization improved from 0647 in the ninth fiveyear plan period to 0774 in the eleventh fiveyear plan period,while there was room for China to improve its energy efficiency.The low efficiency of energy utilization and the high emission of pollutants were the main contributors to low energy efficiency in China.Regional difference was also existed among different regions:the east area ranked the first with the highest efficiency value,the northeast and central area followed,and the west area had the lowest efficiency value.Furthermore,the main contributors to the low efficiency varied greatly from each other.The low efficiency of energy utilization was the main bottleneck factor that restricted the promotion of energy efficiency in the northeast and central regions,and the low economic output was the main reason that restricted the improvement of energy efficiency in the west region,without the consideration of pollution emission.Based on our findings,some policy implications on the improvement of energy efficiency for each region in China were disscused.