Research On The Compensation Mechanism Of PPP Projects In Sponge City Based On Performance Evaluation

In recent years,the problems such as ecology,water pollution and over-exploitation of groundwater become more and more serious.The problems of water control have become an urgent challenge for the sustainable development of cities at present.The proposal of the concept of "sponge city" has pointed out a new direction for the city to solve the problem of water treatment.Unparalleled construction scale and government financial deficit led to "sponge city" construction failed to keep pace with the requirements of the times.The introduction of the PPP model can solve the problem of slow construction due to limited funds.The government can solve the problem of insufficient investment returns in "sponge city" by implementing compensation in the way of project performance appraisal.Under this background,this paper establishes a performance evaluation system of the "sponge city" PPP projects.According to the result of performance evaluation,we study the compensation scheme in line with the expectation of the government and the interest of social capital.The main research content is as follows:First of all,it elaborates the background of the topic,the significance of research,combines with domestic and foreign including "sponge city",PPP performance evaluation,PPP compensation mechanism related literature research;It analyzes the relevant theories of "sponge city" and PPP project performance evaluation: PPP definition and essential characteristics,"sponge city" characteristics,the advantages of PPP used in "sponge city" construction;analyzes the theories of compensation for "sponge city" PPP projects,laying in a certain theoretical foundation for the follow-up "sponge city" PPP project performance appraisal system establishment and compensation mechanism research.Secondly,according to the literature and semi-structured interview with experts to identify 31 performance evaluation indicators.The questionnaire was used to rate the importance of indicators and the data was processed by factor analysis,constructs the structural equation model of performance evaluation system,and draws the following conclusions through the model amendment: Efficiency and Demonstration of Technology plays a direct role in the Construction Quality and Cost Control;the Direct Output of the project has an impact on the performance of the project's Output ofEnvironmental Benefit and Output of Social Economy.Finally,the weight of the indicators,that is,relative importance,was determined by the path coefficients of each variable.Thirdly,in order to study how the government can compensate according to the results of project company performance appraisal,this paper uses the principal-agent model in game theory to establish a two stages game model of compensation.Through the model solution,we find that thelevel of effort taken by the project company relates to the operating income coefficient,the level of environmental benefit output,the level of external output,investment,rewards and punishments coefficient,income distribution ratio,discount coefficient of future earnings and the impact of the performance of the previous stage on the performance of the next stage.The value of rewards and punishments coefficient relates to the operating income coefficient,the cost coefficient,investment,the degree of risk aversion of the social capital,the uncertainty,income distribution,environmental benefit output and external output.Finally,the economic compensation and policy compensation scheme of "sponge city" PPP project are designed based on different management nature.The paper indicates that encouraging profitable projects package with the stronger public welfare projects,constructing performance evaluation standard system,introducing third-party agencies to conduct performance evaluation of the projects,strengthening operational supervision,establishing a compensation mechanism based on performance and improving operation performance payment based on availability payment to guarantee reasonable income of social capital will promote the PPP model to be introduced into the "sponge city" construction.