Research On Government Guarantees For High-speed Rail PPP Projects Based On Bayesian Networks

The government and social capital cooperation(Public Private Partnership)is the important measure of deepening the reform of China's Public service in the construction of infrastructure,which can improve the efficiency and quality of Public service construction,reduce the financial burden and promote the diversification of investors,thus it becomes the most attractive,the most promising infrastructure mode in China.In addition,investors take a huge risk generally,considering the infrastructure projects' large investment scale,long investment recovery period and uncertain demand.The government should provide a certain amount of guarantee or subsidies in the project during the operation of PPP model in infrastructure projects in order to reduce investment risks and attract investors and keep social welfare attribute of infrastructure.Since the high-speed rail PPP projects' construction operation cycle is long,and its influencing factors are highly uncertain and complex,the paper establishes the Bayesian Network(BN)model to describe the transmission relationship of influencing factors.Based on BN's reasoning calculation results and theory of real option,analyzes the level of government guarantee of high-speed rail PPP projects.The main research work of the thesis is as follows:(1)Literature analysis.According to the purpose of this study,the paper has understood the present situation of the study on related issues through searching the keywords of related literature,and has proposed its own ideas on the basis of summarizing the results of previous studies and combining the original knowledge.High-speed PPP project's income mainly decided by the attendance rate and ticket price in concession period,and cost is mainly composed of labor cost,power cost,maintenance cost,and these factors are influenced by macroeconomic development of country and regions.(2)Establish computational model and probabilistic inference.On the basis of literature analysis,the paper has established a bayesian network(BN)that describes the transmission relationship of influencing factors,since the high-speed rail PPP projects' cycle of construction and operation is too long,and its influencing factors are highly uncertain and complicated.This paper also has given the probabilistic inference algorithm of bayesian networks in the process of modeling,and has analyses various income at different stages of economic development level after divide the concession period of high-speed rail PPP projects into six stage.Based on BN's reasoning calculation results and theory of real option,analyzes the level of government guarantee of high-speed rail PPP projects.(3)Case analysis.Taking a high-speed railway project as an example,the concrete application process of the above model is illustrated,and the validity and reliability of the real option calculation model based on bayesian network is further verified.Above studies have shown that the model can predict the level of government guarantee of high-speed rail PPP projects at various combination of influencing factors in view of BN's reasoning calculation results and theory of real option,which provide effective decision-making reference for private investors in the feasibility analysis phase of PPP project and provides a valuable reference for other PPP project in transportation.Accordingly,government departments and the private sector can make decisions based on different expectations and probabilities of earnings.