Research On The Optimization Of Government Subsidy And Its Supervision Strategies In Low-carbon Diffusion

In recent years,the climate environment is getting worse and worse,and the corresponding issue has drawn the attention of countries all over the world.Low-carbon diffusion is one of the important ways to adapt to the climate change and realize the goal of environment treatment.In order to promote low-carbon diffusion,subsidies are one of the widely used incentive measures,and the method is direct subsidy generally.According to the status of government subsidy,the main strategy is to subsidize enterprises and consumers at present,and government subsidies have promoted low-carbon diffusion to a certain extent.However,the disadvantages of subsidies are becoming more and more obvious.For example,with the proportion of low-carbon diffusion increasing,the central and local governments will face increasing pressure on special funds.Meanwhile,it's necessary for an industry to improve product technology and quality level based on market demand,so that the industry can survive in the fierce market competition.Therefore,it is inevitable that the government will gradually reduce subsidies.Moreover,the enterprises in some industries have cheating subsidies through measures such as illegal production and sales forgery,which indicates that the government lacks supervision or does not have enough supervision on low-carbon subsidies.Therefore,the optimization of government subsidy and its supervision strategies is studied in this thesis.Firstly,the influencing factors of low-carbon diffusion are analyzed in terms of subjects and the environment,including enterprises,consumers,the government and noise environment.Based on above contents,the evolutionary game model with the subjects of enterprises and consumers is established considering government subsidies,and the corresponding stochastic evolutionary game model is obtained by combining Brownian motion.Through stability analysis,three cases of the relationship between government subsidies and low-carbon diffusion are presented,that is,government subsidies can promote low-carbon diffusion to the effective state finally,government subsidies cannot promote low-carbon diffusion to the effective state finally,and the relationship between government subsidies and low-carbon diffusion is chaotic.Moreover,the Taylor series expansion is performed on the stochastic evolutionary game model to quantify the uncertainty degree of the noise environment with absolute stability and relative stability probabilities.The effectiveness of the above contents is verified through simulation,and the following conclusions can be obtained:(1)whenthere is low proportion of enterprises adopting low-carbon strategy,and there is low proportion of consumers adopting low-carbon consumption,the effective state of low-carbon diffusion cannot be achieved only relying on government subsidies with different noise intensity.(2)when there are more and more enterprises and consumers adopting low-carbon strategy and low-carbon consumption respectively,the relationship between government subsidies and low-carbon diffusion is chaotic.But with proportions increasing,the quantitative change undergoes qualitative change,the impact of government subsidies on low-carbon diffusion is significant,and the low-carbon diffusion can be a success with different probabilities.(3)the low-carbon diffusion in enterprises has hysteretic nature,and the influence of consumers on enterprises decision about low-carbon strategy adoption is higher than the influence of enterprises on consumers decision about low-carbon consumption.Secondly,in this thesis,a three-party evolutionary game model is established considering the subjects of the government,enterprises and consumers.According to the characteristics of this model,the model is converted into four evolutionary game models with different government subsidy strategies(including no subsidy,only subsidies to enterprises,only subsidies to consumers and subsidies to both agents).Meanwhile,static and dynamic equilibrium analysis are performed on these four models,where,the static equilibrium analysis mainly means the equilibrium point problem with different government subsidy strategies,and the dynamic equilibrium analysis mainly means seven kinds of cases according to different initial values,so that the results of low-carbon diffusion in enterprises and consumers are analyzed when there is no periodic fluctuation and when there is periodic fluctuation.Moreover,the question of how low-carbon subsidy decreases is studied in this thesis further.Different subsidy decreasing cases are given,as well as the judgment criteria of the optimal subsidy decreasing case.According to the differences of subsidy decreasing methods for different subsidy subjects,nine different subsidy decreasing cases and the optimal subsidy decreasing case are obtained.The following conclusions are obtained:(1)the government can adjust the subsidy strategy dynamically,according to the initial state of the system.(2)when there is periodic fluctuation,and the initial state meets certain conditions,low-carbon diffusion can also be a success even with no government subsidies.(3)as for low-carbon diffusion,it may be better to pull the low-carbon market through the demand side than to push the low-carbon market through the supplier side.(4)as for the diffusion of the new energy vehicle BYD E6,the optimal subsidy decreasing cases are that the decreasing method for consumers is stage decrease,and the method for enterprises can be linear decrease,non-linear decrease or stage decrease.Thirdly,in this thesis,the evolutionary game analysis is carried out on government low-carbon subsidy supervision.The evolutionary game model considering enterprises and the government is established,and based on different parameter relationships,four evolutionary equilibrium cases are obtained,that is:(1)the enterprise selects ‘no cheating' strategy,and the government selects ‘no supervision' strategy.(2)the enterprise selects ‘no cheating' strategy,and the government selects ‘no supervision' strategy.(3)the system has four saddle points,and there is no evolutionary stable strategy.(4)the enterprise selects ‘cheating'strategy,and the government selects ‘no supervision' strategy.As for the first two cases,the final stable strategies are the same,but the corresponding evolution processes are different.The third case often occurs and the fourth case hardly exists in real life.Thus as for the third case,the influences of three parameters(including supervision cost,the government loss with no supervision,and the potential loss of enterprises because of cheating subsidy)on the strategies of the government and the enterprise are researched further.The simulation result shows that:(1)the choices of enterprises and the government have an effect on the behavioral expectation of each other in the next period.(2)it's beneficial for low-carbon diffusion when the supervision cost decreases,the government loss with no supervision and the potential loss of enterprises with cheating subsidy increase.Therefore,the government should adopt supervision strategies in the long run.Finally,the optimization problem of government subsidy supervision strategies in low-carbon diffusion is studied in this thesis.Two evolutionary game models are established including no supervision and supervision on low-carbon subsidy respectively,and the corresponding equilibrium points are analyzed.Meanwhile,the optimal supervision strategy is researched further.Where,three supervision strategies are given,that is,supervising all the enterprises randomly,supervising the enterprises which declare for high low-carbon subsidy randomly and supervising the enterprises which are given high low-carbon subsidy randomly.Based on two optimization indexes including supervision efficiency and supervision stability,the decision index of the optimal supervision strategy is obtained.Then the small-world network model is established,the above contents are simulated,and the sensitivity analysis ispresented with three parameters including noise environment,supervision cost and punishment cost.The simulation result shows that:(1)the optimal supervision strategy is to supervise the enterprises which declare for high subsidy randomly,the corresponding optimal supervision probability is 0.48,and the overall optimal supervision probability is 0.24.(2)the supervision efficiency and income stability of supervision strategies cannot be both obtained.However,in order to maximize the benefits of both agents,the measure of considering efficiency first,then stability can be taken into account.(3)when there is more noise in the environment,the average benefits of both agents are lower,and the benefit stability is worse.When the supervision cost is higher,the result is the same as the situation with more noise in environment.However,the increase in punishment cost does not necessarily bring about the increase in benefit.When punishment cost increases to a certain extent,and continues to increase,the benefits of both agents reduce first,and then increase,and the benefit stability becomes worse first,and then better.Moreover,to avoid enterprises cheating subsidy effectively,the optimal boundary condition is obtained according to the perfect Bayesian equilibrium of the signaling game theory,and the effectiveness of this condition is verified through simulation.As can be seen from above contents,this thesis analyzes the questions like ‘why subsidize,who are given the subsidies,how to subsidize' and ‘why supervise,who are supervised,how to supervise'.The research in this paper provides theoretical bases for policy formulation of government subsidies and the corresponding supervision strategies.Meanwhile,the analysis of the evolution mechanism among various subjects with government subsidies and the corresponding supervision strategies helps the government understand the diffusion law of low-carbon in enterprises and consumers from the global aspect,and provides theoretical support for the formulation and implementation of government subsidy strategies and the corresponding supervision strategies.