Spatial-temporal variation of regional energy efficiency and its causes in China, 1990-2009

This paper used DEA model and correlation method to calculate the energy efficiency of 31 regions including Taiwan from 1990 to 2009, and revealed the spatial-temporal variation. It also testified empirically the relations between energy efficiency and the industrial structure, the energy consumption structure, the technical progress and the degree of opening-up. Furthermore, the paper put forward the direction of policy-making for improving regional energy efficiency. The values of this paper was that it had provided advanced analytical tools and a research platform for Chinese economic researchers, also offered policies basis for the governments. The results showed:(1) as a whole, since the 1990s, there was a slow-growing trend of energy efficiency in Chinese mainland, but it was still at the middle level and lower than Taiwan.(2) As stimulus, large-scale investment of production factors played an even greater role in promoting energy efficiency than the progress of science and technology, but the latter had a greater impact on the extent of energy efficiency improvement.(3) In term of spatial differentiation, the energy efficiency was high and stable in the eastern region, but it was low and decreasing in the western region.Meanwhile, there was an increasing trend in the central and northeastern regions, especially,the northeastern region showed significant growing characteristics. According to the sequence from high to low, technical efficiency of the eastern region was the highest, and the central region took the second place, the northeastern region was the third one, and the western region was the lowest one. Scale efficiency differentiated obviously, the sequence from high to low could be given as below: the eastern region, the central region, the western region, and the northeastern region was the lowest that affected by the national market demand.(4) At two different scales of the national level and provincial level, the suitability and contribution of same factors showed obvious differences. At the national level, advance of science and technology, development of non-agriculture industries, growth of foreign trade, and dependence on coal were the main causes of changes in energy efficiency. Specifically,development of non-agriculture industries and dependence on coal promoted the growth of scale efficiency, while growth of foreign trade dragged increase of scale efficiency. The advance of science and technology and development of non-agriculture industries facilitated the promotion of technical efficiency. At the provincial level, only growth of foreign trade showed a positive correlation with energy efficiency.(5) In process of promoting energy efficiency in mainland China, three aspects should be correctly recognized, including industrial structure, the energy market reform and the development of foreign trade. On one hand, we should pursue development by taking a new road toward industrialization to improve the industrial structure and preserve energy resources, and should be committed to making efforts to diversify the energy mix and enhance the share of clean and renewable energy in order to meet the enormous energy requirements in the future. On the other hand,the proportion of energy embodied in the commodities China exports had been much higher than that for other countries for a long time, which was a challenge to China's energy security and sustainable development. From this point, in the medium and medium to long term,carbon emission tax and environmental tax should be designed and implemented to strengthen export control of energy-intensive products.