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June, 2014 Journal of Resources and Ecology J. Resour. Ecol. 2014 5 (2) 97-104 DOI:10.5814/j.issn.1674-764x.2014.02.001 www.jorae.cn Vol.5 No.2 Article Regional Energy Efficiency in China Based on a Three-Stage DEA Model HUANG Dechun, DONG Yuyi, ZHANG Changzheng* and LIU Bingsheng Business School of Hohai University, Nanjing 210098, China Abstract: Energy is the material basis for social development and is closely related with the economy. Energy shortage, a low utilization rate of energy and the deterioration of the environment have become the main restrictions of economic development in China. Therefore, studying energy efficiency has a practical significance for developing a harmonious and sustainable energy economy and building a conservation-minded and harmonious society. Here, based on the three-stage DEA model we analyzed the energy efficiency of 29 provinces in China in 2009, set up an evaluation index system of energy efficiency to compare differences in energy efficiency among regions and provide regions with theoretical guidance to adjust energy consumption strategy and improve energy efficiency. We divided technical efficiency into pure technical efficiency and scale efficiency, analyzed energy efficiency with its numerical value and added environment variables to perfect the results. We found that scale efficiency is overestimated before eliminating external factors and environment variables and pure technical efficiency is underestimated. To solve this problem, regions should expand the scale of the enterprises and pay more attention to energy efficiency. The scale returns of most provinces in the third stage are increasing (except Shandong province), which shows that many enterprises are too small to reflect the economy scale. Therefore, all regions except Shandong should increase their energy inputs to obtain the economy scale of energy utilization. From a regional perspective, eastern energy efficiency is highest and western is the lowest. All regions should increase the size of enterprises to realize the scale economy. Central and western regions in China should strengthen mutual cooperation, bring into play their respective advantages, exploit new energy and new technology and improve the utilization ratio of energy. Key words: regional energy efficiency; three-stage DEA model; technical efficiency; pure technical efficiency; scale efficiency 1 Foreword China achieved rapid economic growth through reform and opening up over the last three decades. However, such achievement was made with a cost of energy and to the environment including natural resource shortages, energy depletion and environmental deterioration. The Chinese Government stated in the Eleventh Five-year Plan that “GDP energy consumption shall be reduced by about 20% over the end of the Tenth Five-year Plan period, while major pollutants emission shall be reduced by 10% on the basis of 2005”. Thus, in this context, studying and improving regional energy efficiency will facilitate China’s overall economic competitiveness as well as sustainable and healthy economic development. The evaluation of energy efficiency traditionally involves analyzing inter-provincial and interregional energy differences, or energy consumption intensity of industrial sectors. Selected evaluation indicators are mainly divided into single-factor and total-factor energy efficiency indicators. However, the single-factor energy efficiency indicator, only taking into account the effective output of single energy input rather than other influencing factors as capital and labor force, has huge defects. In recent years, many have adopted total-factor indicators to evaluate energy efficiency, while the method of Data Envelopment Analysis (DEA) is generally applied. With regard to analysis Received: 2013-07-19 Accepted: 2014-03-03 Foundation: this work was supported by National Social Science Fund of China (11BGL088), the Major Program of National Social Science Found (11&ZD168), National Natural Science Foundation of China (G0213), and Science Foundation of the Chinese Education Commission (11JHQ024). * Corresponding author: ZHANG Changzheng. Email: [email protected]. 98 Journal of Resources and Ecology Vol.5 No.2, 2014 of energy efficiency influencing factors, industrial structure and technological progress are regarded as major factors; however, due to differences in data selection time and methods or in indicators selected, factors influencing energy efficiency remain divided. Here, the author made an attempt to overcome the defects of traditional research methods and adopted nonparametric three-stage DEA methods to evaluate energy efficiencies of 29 provinces in China (excluding Tibet, and data of Chongqing is merged into Sichuan). Energy efficiencies in different regions were compared, providing theoretical guidance for adjusting energy consumption strategies and improving energy utilization in different regions. Existing research literature on this topic involves two aspects of energy efficiency: energy efficiency evaluation and analysis on energy efficiency influencing factors. Both single-factor and total-factor energy efficiency indicators have been used to evaluate energy efficiency. For totalfactor evaluation methods, this paper summarizes the dimensions of input indicator, output indicator, research method and research time (Table 1). Gao and Wang (2006), adopting clustering methodology, thought economic development level, industrial structure, investment and energy price were factors influencing energy efficiency. Qiu and Shen (2008), adopting clustering methodology and the Theil method, conducted quantitative analysis on energy efficiency influencing factors using panel data. Li and Wang (2008), through analyzing data from 30 provinces and cities from 1995 to 2005 with a generalized Fisher index, thought regional structural factor was the major factor energy intensity variation. Qu (2009) constructed the panel model of regional energy efficiency with the variables of energy efficiency, technological progress, energy price, industrial structure, industry structure and institutional factor and thought these factors had positive effects in improving energy efficiency in the east but small influence on central and western China. Yang (2009) used multivariate regression analysis on panel data from 29 provinces from 1986 to 2005 and found that structural factors had the greatest influence on energy efficiency, while capital deepening and opening up both had a negative impact on energy efficiency. Energy efficiency evaluation analyses were mainly conducted on total-factor energy efficiency indicators, which offset the defect of a single-factor energy efficiency indicator; however, most studies have adopted DEA or super-efficiency DEA models which could not avoid the influence of environment and errors on the efficiency value. Therefore, analysis with data from different times and regions might be concluded with deviated results. No unified standard system had been formed for analyzing energy efficiency influencing factors. Here, the author adopted the three-stage DEA model proposed by Fried et al. (2002) to evaluate regional energy efficiency in China with the purpose of obtaining more accurate results and proposing more reasonable suggestions. 2 Principles of three-stage DEA model 2.1 The first stage: traditional DEA model Banker et al. (1984) first built the DEA-CCR model in 1978; however, CCR analyzed input and output and calculated efficiency value under the condition of returns to scale remaining constant, which was contrary to the practical situation. Coelli et al. (1998) introduced the DEABCC model which decomposed the technical efficiency (TE) in the CCR model into pure technical efficiency (PTE) and scale efficiency (SE), i.e. TE=PTE×SE. This more accurately reflects operations and the management level of decisionmaking units. The BCC model may be divided into input oriented and output oriented models. Where, the former is to reduce resource input to the greatest extent to improve efficiency under the condition that the output remains unchanged, while the latter is to increase output efficiency evaluation under the condition that the input factors remain unchanged. As for energy efficiency evaluation, it is easy to control input, but controlling output is relatively difficult. Therefore, an input oriented BCC model is adopted in this paper. Suppose there are n decision making units (DMU), each with m input and s output; xik (i=1, 2, …, m) is the ith input variable of the kth decision making unit; yjk (j=1, 2, …, s) is the jth output variable of the kth decision making unit. Then, calculation of total efficiency of the pth decision-making unit is converted into a linear programming problem: Table 1 Literature analysis of energy efficiency evaluation. Author-Year Wu and Wu 2009 Data period 2006 Yan and Tang 2009 Wei and Shen 2007 Cai and Xiao 2010 1996–2006 1995–2004 1998–2007 Lin and Xu 2010 1997–2008 Input indicator Total employees, total energy consumption and depreciation of fixed assets Energy, labour force and capital stock Capital stock, labour force and energy Capital stock, labour force, coal consumption and oil consumption Labour force, capital stock and total energy consumption Output indicator Regional GDP Research method DEA GDP GDP GDP and total industrial waste gas emission Economic output DEA DEA Super-efficiency DEA DEA 99 HUANG Dechun, et al.: Regional Energy Efficiency in China Based on a Three-Stage DEA Model min θ { X ni = X ni + max Z i β ∗ i n }− Z β i n + max {Vni } − Vni i n=1, 2, … N, i=1, 2, …, I (3) * s.t (1) where, X1=(x11, x22, …, xm1), Y1=(y11, y21, …, ys1) and the model is called a BCC model. θ is the total efficiency value of investigated decision-making unit, and 0≤θ≤1. When θ=1, the investigated decision-making unit is a point on efficient frontier plane, hence it is effective. For ineffective unit of θ<1, 1–θ is the proportion of redundant input by investigated decision-making unit. 2.2 The second stage: adjusting input indicator variable The slack variables of input and output analyzed in the first stage will be influenced by external environmental factors, random error and internal management factors. Traditional DEA models, instead of accurately reflecting whether the influence on efficiency comes from internal management or external environment and random error, attributes all influencing factors to internal management. Therefore, Timmer (1971) introduced stochastic frontier analysis (SFA) to consider the influence of external environmental factors on relative efficiency. Suppose the nth input value of the ith DMU is Xni and the slack variable is Sni, then Sni=Xni–Xnλ>0. According to Batese and Coelli (1995), the relation model between slack variable and environment variable is: Sni = f(Zi, βn)+Vni+Uni n=1, 2, …, N, i=1, 2, …, I (2) where, S ni is the slack variable of the n th input of the i th decision-making unit, Z 1=(z 1i, z 2i, …, z ki) presents k environmental variables; f(Zi,βn) represents the influence of environmental variable on input slack variable S ni; generally, f(Zi, βn)=Zi, βn; Vni+Uni is the combined error term; suppose Vni−N(0, σ2vn) reflects random error item, Uni reflects management inefficiency and obeys a truncated normal distribution, i.e. Uni−N(μ, σ2vn) and Vni is independent from and uncorrelated to Uni. When γ=σ2vn/(σ2vn+σi2) is close to 1, the influence of management factor predominates; when γ=σ2vn/(σ2vn+σ2vn) is close to 0, the influence of random error predominates. Through adjusting input variable data of the nth decisionmaking unit with the result of SFA model regression and eliminating the influences of environmental factor and random error, an efficiency value purely reflecting management level can be calculated. The adjustment formula is as follows: where, X ni is input after adjustment; Xni is original input value. The first square bracket in Formula (3) indicates all decision-making units are adjusted to be under the same external environment and the second square bracket indicates random errors of all decision-making units are adjusted to the same to make all decision-making units under the same external environment and fortune. 2.3 The third stage: DEA model after adjustment In this stage, input the input data after adjustment in the second stage and original output data into the DEA model to calculate the relative efficiency value; then the result is the efficiency value reflecting management level after eliminating the influence of environmental factor and random factor and reflects efficiency value of the management level. 3 Variable selection and data source 3.1 Selection of input and output variables Energy, labour force and capital were selected in this paper as three input factors. Wherein, energy input factor is represented by energy consumption, which has been converted into 10 000 ton standard coal; labour force input is mainly represented by employees at the end of current year; and capital input is represented by capital stock, which is generally estimated with the perpetual inventory method at the end of each year in case the data of capital stock cannot be obtained directly. This paper follows Zhang et al. (2004), wherein, the economic depreciation rate is 9.6% of total fixes assets of each province is adopted as the depreciation rate. Calculation method: Ki,t=Ii,t +(1–δi)Ki.t-1, where Ki,t is the capital stock in the tth year of region i, Ii,t is the investment of region i in the tth year, δi is fixed assets depreciation rate of region i. The selection of output variable takes into account that energy input results in rapid economic and industrial development. Therefore, in this paper, total industrial output value and regional GDP are selected as output variables. 3.2 Selection of environmental variable Generally, environmental variable means the factor which may influence energy utilization efficiency but is beyond the scope of subjective control. In consideration of the factors influencing energy utilization, in this paper, technological progress and industrial structure are adopted as environmental variables. Technological progress becomes increasingly influential to energy utilization efficiency. Advanced energy conversion technologies may reduce energy waste and energy-saving technologies may directly reduce energy consumption per unit product. Under the current condition with increasingly 100 Journal of Resources and Ecology Vol.5 No.2, 2014 less traditional energy, every country increases the input in scientific and technological research and development to find new energy and technologies. This paper adopts R&D funding as the measurement indicator of technological progress. Among the three industries, the secondary industry has high energy consumption. Therefore, the secondary industry development in each region is directly relevant to energy utilization and industrial structure is represented by the proportion of the secondary industry in GDP. 3.3 Data source In consideration of data integrity and availability, this paper selects data for 29 provinces, municipalities and autonomous regions in 2009 (Tibet was not selected due to the incompleteness and data of Chongqing is merged into that of Sichuan). Except the R&D fund from the China Statistical Yearbook on Science and Technology in 2010, all others are from the China Statistical Yearbook in 2010. 4 Empirical analysis 4.1 Traditional DEA empirical result in the first stage Adopting the input oriented BCC model, technical efficiency (TE), pure technical efficiency (PTE) and scale efficiency (SE) are obtained in the first stage (Table 2). In addition, the difference value, i.e. slack value, between the ideal value and actual value of input variable can be obtained, which will be applied in the next stage. According to Table 2, taking no account of the influences of environmental factor and random error, the average technical efficiency, average pure technical efficiency and average scale efficiency of these provinces and cities in China are 0.863, 0.917 and 0.943 respectively. Five provinces have technical efficiencies reaching 1, i.e. the technology frontier, which are Beijing, Tianjin, Shanghai, Guangdong and Gansu; however, the other 24 provinces are under an inefficient state with large demand. Most provinces have scale efficiencies larger than pure technical efficiencies, which means that the technical inefficiencies of most provinces have resulted from pure technical inefficiency but not scale inefficiency. According to results obtained in the first stage, pure technical inefficiency is the major factor restricting the energy utilization rate; however, we still have to further analyze if pure technical efficiency is underestimated or scale efficiency overestimated without considering the influences of the external environment and random error. 4.2 SFA regression result in the second stage Let slack value of each input variable analyzed in the first stage be the dependent variable and environmental variable R&D funds and number of industrial enterprises be independent variables to analyze if external environmental variable influences the difference between ideal and actual input variables. If the analysis shows that environmental variables will influence input variable difference, Formula (3) will be adopted to eliminate external environmental factors, thereby to obtain the input variable X *ni after eliminating external environmental variables. Frontier 4.1 was used to obtain regression results (Table 3). According to Table 3, the slack variables of R&D funding and proportion of the secondary industry in GDP to capital stock and energy consumption passes the test with 1% significance and the slack variable of proportion of the Table 2 Comparison of energy efficiency between 29 regions in China in 2009. Region Beijing Tianjin Hebei Shanxi Inner Mongolia Liaoning Jilin Heilongjiang Shanghai Jiangsu Zhejiang Anhui Fujian Jiangxi Shandong TE 1.000 1.000 0.773 0.982 0.931 0.881 0.812 0.856 1.000 0.920 0.849 0.941 0.858 0.830 0.841 PTE 1.000 1.000 0.779 1.000 0.956 1.000 0.815 0.861 1.000 1.000 0.862 0.950 0.872 0.880 1.000 SE 1.000 1.000 0.992 0.982 0.974 0.881 0.996 0.994 1.000 0.920 0.985 0.991 0.983 0.943 0.841 RTS – – drs drs irs drs irs irs – drs drs drs irs irs drs Region Henan Hubei Hunan Guangdong Guangxi Hainan Sichuan Guizhou Yunnan Shaanxi Gansu Qinghai Ningxia Xinjiang Average value TE 0.795 0.946 0.899 1.000 0.853 0.801 0.779 0.798 0.743 0.896 1.000 0.683 0.672 0.675 0.863 PTE 0.801 0.991 0.925 1.000 0.897 1.000 0.803 0.861 0.763 0.901 1.000 1.000 0.957 0.709 0.917 SE 0.993 0.955 0.972 1.000 0.951 0.801 0.971 0.928 0.974 0.994 1.000 0.683 0.702 0.952 0.943 RTS drs drs irs – irs irs drs irs irs drs – irs irs irs Notes: TE is technical efficiency; PTE is pure technical efficiency; SE is scale efficiency; TE=PTE×SE; RTS is returns to scale; ‘irs’ is increasing returns to scale; ‘drs’ is decreasing returns to scale; and ‘–‘ means the returns to scale remain unchanged. 101 HUANG Dechun, et al.: Regional Energy Efficiency in China Based on a Three-Stage DEA Model Table 3 SFA regression results. Employee slack variable Constant value R&D fund Proportion of the secondary industry in GDP Sigma-squared Gamma Log likelihood Coefficient value –1.38E+03 –5.66E–06 2.15E+03 2.04E+06 1.00E+00 –2.29E+02 T test value –1.38E+03*** –1.78E–01 2.51E+03*** Total energy consumption slack variable Coefficient value T test value Coefficient value T test value –6.92E+03*** –6.92E+03*** –4.68E+03 –4.68E+03*** –6.756E–05 –1.75E+01*** 1.85E–04 1.36E+01 1.28E+04 1.28E+04*** 7.03E+03 7.03E+03*** 2.04E+06*** 2.98E+03*** Capital stock slack variable 2.32E+07 1.00E+00 –2.65E+02 2.32E+07*** 3.51E+07*** 1.77E+07 1.00E+00 –2.60E+02 1.77E+07*** 1.43E+06*** Notes: T is the indicator to test if explaining variable has significant impact on explained variable; *** represents the test with 1% significance level; ** represents the test with 5% significance level; * represents the test with 10% significance level. second industry in GDP also passes the test, indicating that environmental factors have a significant influence on input redundancy. Formula (3) shall be used to eliminate external environment variables and random factor and finally make all provinces the same external environment characteristic in the third stage. Input slack variable means possible reduced input through improving operation and management levels; therefore, if the environmental variable is positively correlated with input slack variable, increasing the environmental variable input will go against improving energy utilization rate. It can be seen from Table 3 that regression coefficients of R&D funding input to two slack variables of employees and capital stock are both negative and both pass the test at a 1% significance level, indicating that increasing R&D funding input will increase the energy utilization rate. Similarly, the secondary industries are mostly high energy-consuming or extensive industries, which also have huge energy consumption and result in serious pollution, hence increasing the proportion of the secondary industry in GDP will restrict improving the energy utilization rate, which is also consistent with the actual situation. Reasonably adjusting industrial structure and increasing scientific and technological R&D funding input to develop new technologies are perfect ways to improve energy utilization. 4.3 DEA empirical results after adjusting input in the third stage After adjusting input variables of energy efficiencies of 29 provinces and municipalities in China in 2009, input the adjusted variable (this variable is the value obtained after eliminating environmental variable and random factor with Formula (3)) and the original output variable into DEAP2.1, then the technical efficiency taking no account of the external environmental factor and random error can be obtained (Table 4). Through comparing results of the first stage, it can be seen that the energy efficiency values before and after adjustment are different to some extent. The average technical efficiency is reduced from 0.863 to 0.801 and scale efficiency value declines from 0.943 to 0.802 and pure technical efficiency shows great growth from 0.917 to 0.998. According to further research, scale efficiencies of all provinces and regions all reduce before and after adjustment, which indicates that diseconomy of scale is the cause of low energy efficiency, unlike the result of the first stage that indicated that low energy efficiency resulted from pure technical inefficiency. After eliminating environmental and random factors, there are 15 provinces witnessing a decrease in technical efficiency value, indicating that they were overestimated because of their better environmental factor or fortune; 11 provinces witness reducing efficiency values because of their poorer external environment or fortune but not low technical level. Without eliminating the external environmental factor and random factor, all provinces have overestimated scale efficiencies and underestimated pure technical efficiency and the overestimation extent is higher than underestimation extent, resulting in overestimation of the technical efficiency value. 4.4 Analysis on overall and regional differences of energy efficiencies in provinces and municipalities in China Eliminating the influence of external environmental factor and random factor, analysis in the third stage may reflect practical operating conditions in energy utilization. Therefore, integrating analysis results in the third stage with the practical condition allows for deeper analysis. 4.4.1 Overall analysis According to analysis results in the third stage, the comprehensive technical efficiency value is 0.801 with a low overall level and pure technical efficiency value of 0.998 with high level and good performance, indicating that most enterprises have matured decision-making and management levels regarding energy utilization. On the other hand, low 102 Journal of Resources and Ecology Vol.5 No.2, 2014 Table 4 Comparison of energy efficiency between 29 regions in China in 2009 after adjusting input in the third stage. Region Beijing Tianjin Hebei Shanxi Inner Mongolia Liaoning Jilin Heilongjiang Shanghai Jiangsu Zhejiang Anhui Fujian Jiangxi Shandong TE 0.808 0.956 0.965 0.974 0.767 1.000 0.885 0.858 1.000 0.990 0.835 0.926 0.704 0.657 0.966 PTE 1.000 1.000 1.000 1.000 0.997 1.000 0.999 1.000 1.000 1.000 1.000 1.000 0.999 0.998 1.000 SE 0.808 0.956 0.965 0.974 0.769 1.000 0.886 0.858 1.000 0.990 0.835 0.926 0.705 0.658 0.966 RTS irs irs irs irs irs irs irs irs – irs irs irs irs irs drs Region Henan Hubei Hunan Guangdong Guangxi Hainan Sichuan Guizhou Yunnan Shaanxi Gansu Qinghai Ningxia Xinjiang Average value TE 0.956 0.960 0.803 1.000 0.695 0.222 0.981 0.592 0.735 0.937 0.813 0.248 0.278 0.718 0.801 PTE 1.000 1.000 0.995 1.000 0.990 1.000 1.000 0.987 0.994 1.000 1.000 1.000 1.000 0.990 0.998 SE 0.956 0.960 0.806 1.000 0.702 0.222 0.981 0.600 0.739 0.937 0.813 0.248 0.278 0.725 0.802 RTS irs irs irs – irs irs irs irs irs irs – irs irs irs Notes: TE is technical efficiency; PTE is pure technical efficiency; SE is scale efficiency; TE=PTE×SE; RTS is returns to scale; ‘irs’ is increasing returns to scale; ‘drs’ is decreasing returns to scale; and ‘–‘ means the returns to scale remain unchanged. comprehensive energy efficiency has mainly resulted from low scale efficiency in each province or municipality, which in reality is mainly reflected in insufficient importance attached by most enterprises to energy utilization as well as small scale and low status in decision-making of the enterprises. However, with overdevelopment of energy resources, less and less energy resources are available with higher and higher energy utilization costs, and low energy utilization efficiency becomes an increasingly important factor restricting enterprise development. To improve comprehensive energy utilization efficiency, the scale energy utilization rate must be enhanced. 4.4.2 Regional analysis According to traditional regional classification methods we divide China into three regions: east (Beijing, Tianjin, Hebei, Liaoning, Shanghai, Jiangsu, Zhejiang, Fujian, Shandong and Guangdong), central (Shanxi, Jilin, Heilongjiang, Anhui, Jiangxi, Henan, Hunan, Hubei and Hainan) and west (Inner Mongolia, Sichuan, Guizhou, Yunnan, Shaanxi, Gansu, Qinghai, Ningxia and Xinjiang). According to respective statistical data for these regions in the first and third stage, regardless of adjustment, the east always has the highest technical efficiency, central China occupies second place and the west has the lowest. As the efficiency values calculated in the third stage are more accurate, regional efficiency differences are analyzed based on data of the third stage. As for comprehensive technical efficiency, the east and the west are 0.922 and 0.676, the highest and the lowest respectively. However, the values of pure technical efficiencies in all regions are all quite high with small difference; the difference of scale efficiency is the same with that of comprehensive technical efficiency. Of course, exceptions exist, e.g. Hainan in the central group has only an efficiency of 0.222, which is quite low, while the ones of Sichuan and Shaanxi in the west are 0.981 and 0.937 respectively. The above data show that scale efficiencies in these regions are relatively smaller than pure technical efficiency values; therefore, the enterprises should improve scale economical efficiency of energy utilization and attach importance to energy utilization. The central region and east should enhance cooperation to narrow the gap. High efficiency value in the east indicates that, supported by the developed economy and with powerful policy support and abundant talent, the east does a better job in development of new energy and new technologies than inland regions. Therefore, central and western China should learn advanced management experience and technologies from the east and introduce innovative thinking methods and energy-saving and net energy technologies to improve energy efficiency, thereby realizing coordinated development of the regional economy. High pure technical efficiencies in the table do not really imply high pure technical efficiencies in these regions, because DEA measures relative efficiency and it only indicates convergent pure technical efficiencies of these regions. Therefore, these regions still need to improve operation and management levels and strengthen competitiveness. 5 Conclusions After eliminating random error and external environmental factor with the SFA model, comprehensive efficiency values, pure technical efficiency values and scale efficiency values of provinces and municipalities all increased or HUANG Dechun, et al.: Regional Energy Efficiency in China Based on a Three-Stage DEA Model reduced to some extent. Underestimated pure technical efficiency and overestimated scale efficiency indicate that external environmental factor, having great influence on energy efficiency, should be eliminated by analyses. Analysis in the third stage shows that all regions are witnessing progressive increasing in returns to scale (except Shandong where returns to scale is decreasing progressively, indicating that Shandong with large energy utilization scale, has realized economical efficiency of scale); therefore, all regions but Shandong should increase energy input for the purpose of economical efficiency of scale in energy utilization. Regionally, energy efficiencies in the central, east and west are significantly different. The east has the highest energy efficiency, the central region takes second place and the west has the lowest. This pattern indicates that supported by a developed economy and powerful policy support and advanced talent, the east does a better job in development of new energy and new technologies than other regions. Recommendation 1: Enlarge enterprise scale to realize economical efficiency of scale. According to the analysis result in the third stage, low scale efficiency is the major factor resulting in low technical efficiency. Combining with reality, there are numerous small and mediumsized enterprises in China. Many small enterprises only attach importance to the result rather than energy utilization efficiency in the primary stage, resulting in scale diseconomies of energy utilization. Therefore, small and medium-sized enterprises should pay attention to this problem. Recommendation 2: Continuously promote technological progress to enhance energy utilization rate. The east should take full advantage of abundant funds and advanced technologies to develop new energy technologies, e.g. solar energy, hydrogen energy, nuclear energy, electrochemical power source and biomass energy. The central region should give full play to the advantages to selectively cultivate high and new technology industry and continuously improve energy-saving and cleaning technologies. The west should learn advanced management experience and technologies from central China and the east to improve energy efficiency. Recommendation 3: Devote to developing high-tech, high value-added, low-energy and low-pollution industries and properly reduce production scales of high-energy consumption products, e.g. the secondary industries mostly 103 have high energy consumption and large proportion of the secondary industry in GDP is also found in the statistics. Therefore, the ratio of the primary, secondary and tertiary industries should be coordinated to improve energy utilization. References Banker R D, A Charnes, W W Cooper. 1984. Some models for estimating technical and scale inefficiencies in data envelopment analysis. Management Science, (30):1078-1092. Battese G E, T J Coelli. 1995. A model for technical inefficiency effects in a stochastic frontier production function for panel data. Empirical Economics, 20(2): 325-332. Cai X C, Xiao X A. 2010. 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Wuhan: Huazhong University of Science and Technology. (in Chinese) Zhang J, Wu G Y, Zhang J P. 2004. The estimation of China’s provincial capital stock: 1952-2000. Economic Research Journal, (10):35-44. (in Chinese) 104 Journal of Resources and Ecology Vol.5 No.2, 2014 基于三阶段DEA模型中国区域能源效率研究 黄德春,董宇怡,张长征,刘炳胜 河海大学商学院,南京 210098 摘 要:能源短缺、利用率低、环境恶化已经成为制约我国经济发展的重要环节。本文运用三阶段DEA模型对中国29个省 市2009年的能源效率进行了分析。文章将技术效率分为纯技术效率和规模效率,并利用其数值来分析能源效率,同时,加入环 境变量来分析完善上述计算结果。结果表明,在剔除外部因素和环境变量以前规模效率被高估,纯技术效率被低估。大部分省 在第三阶段计算出的规模收益是递增的,这说明很多企业规模较小不能体现出规模经济性。从区域上来看则是东部地区的能源 效率最高,中部次之,西部最低。针对这一结果,本文给出几点建议:中西部地区应加强合作,发挥各自优势,开发新技术新 能源,提高能源利用率,促进经济健康发展。 关键词:区域能源效率;三阶段DEA;技术效率;纯技术效率;规模效率