Research On The Concession Pricing Of PPP Sewage Disposal Projects Based On System Dynamics

The pricing of sewage disposal fee is a key for private sector to recovery capital.But there is no definite standard for China's sewage disposal fee pricing at present because of the pricing professional,extensive and complicated process,coupled with the lack of information disclosure system and feedback system.This caused the phenomenon of unreasonable sewage disposal charging,the difficulty to guarantee the basic interests of the enterprise.In this regard,this thesis tries to establish a pricing model under PPP mode based on System Dynamics,in the hope of providing a more reasonable method for sewage disposal fee pricing.This thesis firstly distinguish the factors of sewage disposal fee pricing under PPP mode combined with engineering economy and relevant researches.They are franchise,rate of return on investment,inflation level,the number of urban population and other factors.Then divide factors to several levels by using Interpretative Structural Modeling Method,clarifies the direct and the root factors that affect franchise pricing.On this basis,causal loop diagram and flow inventory for sewage disposal PPP project on SD are established.The causal loop diagram is used to reflect the positive and negative relationship between the various factors,the positive and negative feedback loops in the system.Flow inventory and SPSS are combined to quantify the quantitative relationship among variables.The calculation equations of each variable are given.Finally the data of a specific sewage disposal project are used to simulate the model to certify its rationality;adjustment measures and suggestions for sewage disposal project in price adjustment are given.The results show that the PPP project pricing model based on SD reflect the changes in the quantity of sewage treatment,the net present value of the project,the price of the fee and so on.The simulation is more consistent with the actual social and economic development,providing reference for the price adjustment of the project.