Research On Innovation Efficiency Evaluation Of Energy Conservation And Environmental Protection Listed Companies Based On The Three-stage DEA Model

At present,China's economy continues to grow steadily,and the economic development model of high pollution and high energy consumption is not desirable.Energy conservation and environmental protection industry,as a significant guarantee for the sustainable development of China's economy and a critical force to promote the industrial transformation,is listed as the top of the seven strategic emerging industries.The rapid development of the industry is inseparable from the support of capital,knowledge and technology,and the results of its innovation affect the economic development and technological progress of the country.At the moment,it has invested a great deal of labor power,financial resources and material resources for energy conservation and environmental protection industry in our country,but the quality of the output results are with the good and the bad intermingled.Some listed companies' technical level have reached the international leading level,while it will be difficult to maintain the survival and development for some of the listed companies.Given the innovation efficiency is vital for the development of energy conservation and environmental protection industry,the promotion the efficiency of innovation can accelerate to tap the potential within the listed companies,to enhance core competitiveness.Therefore,it is necessary to study the innovation efficiency of energy saving and environment protection listed companies,and provide the suggestion according to the present stage of innovation development.In this thesis,based on the existing academic research findings,according to the principles of setting index system of innovation efficiency,combining with the characteristics of energy conservation and environmental protection industries,input indexes and output indexes were selected preliminarly,and the primary indexes were screened by the method of variation coefficient,innovation efficiency evaluation system of the energy saving and environmental protection listed companies is built.In this text,194 energy conservation and environment protection listed companies were selected as the research objects,and the three stage DEA was adopted to evaluate the innovation efficiency.In the first stage of analysis,the traditional DEA method was used to preliminarily measure the innovation efficiency of the three types of listed companies,including energy conservation listed companies,environmental protection listed companies and resource recycling listed companies.Then the influence of environmental factors and statistical noise are eliminated by using similar stochastic frontier regression method in the second stage.In the third stage of analysis,the revised sample data was used again to calculate the efficiency of the third stage by using the DEA model.The measurement results before and after adjustment were compared and analyzed from the four aspects of technical efficiency,pure technical efficiency,scale efficiency and scale revenue.On this basis,three types of listed companies were analyzed in innovation efficiency mode and regional innovation efficiency.The results indicate that the technical efficiency,the pure technical efficiency and the scale efficiency of energysaving listed companies are underestimated.The technical efficiency and the scale efficiency of environmental listed companies are underestimated,the pure technical efficiency of environmental listed companies is overestimated.The technical efficiency and the scale efficiency of resource recycling listed companies is overestimated.Energysaving and environmental listed companies generally show the state of diminishing returns,while the distribution of scale income of resource recycling companies is relatively balanced.Among the three types listed companies,in the efficiency model,the number of listed companies with high efficiency of pure technology and scale efficiency is the most.Technical efficiency,pure technical efficiency and scale efficiency all show the trend that the eastern part is higher than the central and the central is higher than the west.The article puts forward suggestions,aiming at improving the innovation efficiency of energy saving and environmental protection listed companies,and promoting the healthy and sustainable development of China's energy conservation and environmental protection industry.