Research On Technological Innovation Efficiency Of Listed Companies Of New Energy Vehicles Based On Three-stage DEA Model ——Taking Listed Companies In Shenzhen And Shanghai Stock Market As An Example

In recent years,the development of new energy vehicle industry has achieved remarkable results.China has become the world’s first automobile and new energy vehicle market.The new energy vehicle industry development plan（2021-2035）points out that in order to face a more complex market environment,we must seize strategic opportunities,continuously improve the core competitiveness of the industry and promote the high-quality and sustainable development of the new energy vehicle industry.The key to the core competitiveness of the industry lies in the ability and efficiency of technological innovation.Therefore,this paper starts from the enterprise level,and selects 40 new energy vehicle enterprises in five fields including vehicle manufacturing,battery power supply,motor,charging pile and auto parts from the listed enterprises in the new energy vehicle sector of Shenzhen and Shanghai stock market as the research sample to comprehensively measure and analyze their technological innovation efficiency.Combined with the input-output situation of the sample enterprises,through the comparative analysis of the traditional DEA model and SFA model and the comparison of their advantages and disadvantages,this paper finally adopts the Three-stage DEA measurement method,selects the input-output and environmental variables to construct the technical innovation efficiency index system,and uses the Three-stage DEA model to analyze the data of the sample enterprises from 2014 to2020.By decomposing the comprehensive efficiency,we can analyze the relationship between the input factors and output variables of technological innovation from the perspectives of pure technical efficiency and scale efficiency.The specific operation methods of the Three-stage DEA in this paper are as follows: in the first stage,the classical BBC model is used to calculate the comprehensive efficiency of the undivided environmental variables and random interference terms;in the second stage,the influence caused by the environmental variables and random interference terms is separated and calculated based on the calculation results of the first stage;in the third stage,the calculation results of the second stage are used,The separated input factors and output variables are brought back into the one-stage BBC model for calculation.Finally,the comprehensive efficiency value,pure technical efficiency value and scale efficiency value of technological innovation obtained in the first and third stages are compared and analyzed.The analysis results show that:The technological innovation efficiency of China’s listed companies of new energy vehicles is generally low,and the sample enterprises are generally at a moderate DEA ineffective level.The technological innovation efficiency of listed companies of new energy vehicles is highly sensitive to environmental variables.After the second stage adjustment,the results of the first and third stages are compared and analyzed.The decline of pure technical efficiency of China’s listed companies of new energy vehicles is greater than that of scale efficiency,indicating that the low efficiency of technological innovation of listed companies of new energy vehicles is mainly due to the lack of pure technical efficiency.Based on the research results of this paper,this paper puts forward relevant suggestions for the development of new energy vehicle industry from the micro level of enterprises,the meso level of industry and the macro level of government.