交通基础设施项目具有投资高、风险高的特点. 为了刺激社会资本的参与, 政府基于交通需求量进行担保以降低交通基础设施项目的风险、实现共赢. 首先, 运用实物期权理论, 探讨政府对高速公路基础设施交通量进行上下限担保的期权特性, 并在风险共担的视阈下运用改进的 Shapley 值方法确定政府对超过交通量担保上限所带来的超额收益的分配比例; 然后, 结合应用 Black-Scholes 期权定价公式, 对交通量波动条件下高速公路 PPP 项目的政府双边担保价值进行研究; 最后, 通过算例分析测度 PPP 高速公路项目的担保价值.

Transportation infrastructure projects are characterized by high investment and high risks. In order to encourage social capital institutions to invest infrastructure, the government offers traffic volume's guarantee to reduce the risks and achieve win-to-win goals. First, the real option theory is used to analyze the option characteristics of the government's guarantee which is about the traffic volume's upper and lower limits of PPP highways. From the risk sharing perspective, the paper employs the method of Shapley value to determine the government's distribution ratio to the excess earnings resulting from the exceeding traffic volume. Furthermore, it is combined with the Black-Scholes option pricing formula to study the value of the government's guarantee about the traffic volume's upper and lower limits of PPP highways. Finally, the value of government guarantee is calculated through an example of PPP highway project.