Study On The Evolutionary Game Of Government Supervision During The Operation Period Of PPP Projects

The government and social investors participate in the construction and operation of the project through the PPP mode.However,due to the conflict of interests between the two parties,investors may take opportunistic behaviors to pursue the maximization of their own interests,damage the public interests and disturb the market environment.In this context,based on the perspective of punishment mechanism,incentive mechanism and public participation,this paper focuses on how the government can effectively supervise investors and restrain their behaviors during the operation of PPP projects,so as to ensure the success of the projects and safeguard public interests.This paper divides the supervision mode into process supervision and result supervision,and constructs the evolutionary game model between the punishment mechanism,the incentive mechanism,the government supervision mode under the public supervision and the opportunistic behavior of investors by using the evolutionary game theory,simulating the learning and dynamic adjustment process of both sides of the game.The local equilibrium point of the game model is solved by the replication dynamic equation,and then the determinant and trace of the local equilibrium point of the game model are calculated by the jacobian matrix,so as to determine whether there is a stable equilibrium point of the game model.In the case of stable equilibrium point,the final strategy of both sides of the game is the strategic choice corresponding to the stable equilibrium point.Therefore,the size of parameters can be set to influence the way of government regulation and the strategic choice of investors' opportunistic behavior.If there is no stable equilibrium point,that is,there is no set of evolutionary stable strategies between the two parties,then the government regulatory authorities and investors adopt mixed strategy game,and the final result of the game is related to the benefits of both parties and the initial state of the system.Firstly,under the background of the government's punishment mechanism for investors' speculative behaviors,the influences of the punishment parameters,the probability parameters of investors' opportunistic behaviors discovered by the government's result supervision and the parameters of speculative net income on the strategy selection of both sides of the game are analyzed.Secondly,under the background of the government's incentive mechanism of punishing investors' speculative behaviors and rewarding nonspeculative behaviors,the influence of punishment parameters and reward parameters on the strategic choice of both sides of the game is analyzed,and the role of punishment mechanism and incentive mechanism in inhibiting investors' non-opportunistic behaviors.After that,considering the game between the government and the investors under the background of public supervision,the paper analyzes the probability that the public supervision can identify the investors' speculative behavior and the influence of the strategy choice of the two sides of the game,so as to analyze the public supervision and provide reference opinions for the government departments to adopt the strategy choice.Finally,select the PPP sewage treatment project as the research object,using the MAPLE software to punish mechanism,incentive mechanism and evolutionary game model under the public scrutiny of numerical simulation for an example,this paper proposes the methodology system for example and verify,what regulatory mechanisms and strategies for the government to provide advice,so as to minimize the occurrence of opportunistic behavior.