Research On The Calculation Of Government Funding Gap Subsidy For Expressway PPP Projects Based On System Dynamics

With the rapid development of our country’s economy,the construction of expressways has become an important component of infrastructure development.Due to constraints related to fiscal capacity and debt risk,traditional investment models are no longer sufficient to meet the demands of expressway construction.The introduction of social capital and the adoption of the Public-PrivatePartnership(PPP)model can effectively solve the current shortfall in government fiscal investment.In the PPP model,due to the uncertainty of traffic demand and high investment costs of expressway projects,the enthusiasm of social capital participation is often low.Therefore,the government’s reasonable funding gap subsidies are crucial in motivating social capital to participate in project construction and ongoing operation.Consequently,how to scientifically calculate the funding gap subsidies,improve the subsidy effect,reduce project operational risks,and achieve risk-sharing is the key issue for the success of current expressway PPP projects.Regarding the current situation and rationality issue of funding gap subsidies for expressway PPP projects,firstly,through literature research methods,identify and analyze the influencing factors of funding gap subsidy calculation for expressway PPP projects.Secondly,based on system dynamics and utilizing the Vensim PLE software,a causal relationship diagram of the influencing factors of funding gap subsidy calculation for expressway PPP projects is drawn.Building upon the causal relationship diagram,stock and flow diagrams of influencing factors are constructed,and subsequently,a system dynamics equation is established to create a funding gap subsidy calculation model for expressway PPP projects.This model is then applied to actual cases for empirical research to validate its effectiveness.Finally,through dynamic simulation and sensitivity analysis of funding gap subsidies for expressway PPP projects using the model,reasonable recommendations are proposed.Through this research,it is discovered that by utilizing system dynamics,the government can scientifically and reasonably calculate funding gap subsidies for expressway PPP projects.It allows for a more comprehensive dynamic calculation of gap subsidies during project operation,enhancing the flexibility of funding gap subsidies and motivating social capital to actively participate in project construction and operation.Through rational and flexible subsidies,social capital’s enthusiasm for participating in expressway PPP projects is greatly stimulated,leading to social capital obtaining reasonable returns,effective government control of subsidies,and the maximization of public benefits for expressway PPP projects.