Research On Evolutionary Game Of Enterprises Participating In PPP Projects With Considering Third-party Supervision

Since the 21st century,There is a huge demand for public services and public products in our country,According to data from the PPP Center of the Ministry of Finance,by the end of 2016,there were nearly 4,300 PPP projects in the database,with an investment of nearly 7 trillion yuan.Government funds are stretched in the face of huge social demands.In order to alleviate financial pressures,the PPP model has been introduced.Data from the Ministry of Finance of my country show that since 2014,the number of PPP projects across the country has been increasing.However,due to the shortage of government funds and other factors,the implementation rate of PPP projects is not high,and the withdrawal rate is not low.According to the case analysis of failed PPP projects in previous years,the reason for the failure of PPP projects is that some government units lack good contract spirit.Scholars from various countries have also carried out comprehensive research on the credit risk of local governments,but this type of research is mainly based on qualitative analysis,supplemented by quantitative explanations,and lacks quantitative research and analysis.In view of this,this paper establishes a game model of local government and social capital with the help of evolutionary game related tools,and analyzes the evolutionary stability strategy under different conditions,clarifies the factors related to the emergence of local government credit risk,and expounds the underlying reasons behind the emergence of local government credit risk.The research shows that,when there is only a game between local government and social capital,because local government is in a strong position in the game,it is difficult for social capital to effectively restrict the behavior of local government and prevent local government from credit risk.On this basis,in order to ensure the healthy development of PPP projects,the incentive and restraint mechanism of the third-party supervision department is introduced to modify the model,and a tripartite game model is constructed.The evolutionary stability strategies of the three parties are comprehensively analyzed,and eight evolutionary stability strategy points and their stability conditions are obtained.Finally,the model is simulated to verify the validity and correctness of the model.The results show that the initial strategy,incentives and constraints of the regulatory authorities can effectively limit the local government's dishonesty and social capital's breach of contract.In view of the existing problems of PPP projects,this paper puts forward corresponding suggestions from three aspects: the state,enterprises,local governments.This paper provides some theoretical reference for the healthy and orderly development of PPP projects,but there are also some limitations.It is hoped that this study can provide reference and guidance for the healthy development of PPP projects in the future,give full play to the advantages of PPP projects,and provide more effective protection for people's livelihood and well-being.