高铁PPP项目与商业银行风险——影响机理和博弈分析

High-Speed Railway PPP Projects and Commercial Bank’s Risks——Influence Mechanism and Game Analysis

基于不完全契约理论,本文分析了高铁PPP项目中银行过度承担风险的影响机理,并构建三方动态讨价还价博弈模型,计算得出风险分担的最优纳什均衡解。结果显示:契约机制难以有效约束公共部门和私营部门向银行过度转移风险行为;三方威慑作用和损耗系数决定了实际博弈中的风险分担比例;公共部门威慑作用更大,损耗系数更小,处于优势地位,易使私营部门和银行形成"同盟"与公共部门对抗。银行若想降低己方的风险比例,应更多了解对方的信息与谈判策略,减少谈判次数,降低损耗成本。

Based on the theory of incomplete contracts,this paper analyzes the influence mechanism of bank’s excessive risk-taking in high-speed railway PPP projects,and constructs a tripartite dynamic bargaining game model to calculate the optimal Nash equilibrium solution for risk-sharing.The results show it is difficult for the contract mechanism to effectively restrain the behaviors of public sector and the private sector from transferring excessive risks to the bank;the deterrence effects and the attrition coefficients of the tripartite determine the proportion of risk sharing in the actual game;the greater deterrence effect,the smaller attrition coefficient and the dominant position of the public sector make it easy that the private sector and the bank form an"alliance"to confront the public sector.If a bank wants to reduce its own risk proportion,it should learn more about the other party’s information and negotiation strategy,reduce the number of negotiation,and reduce attrition cost.