Abstract: In PPP (public-private partnership) projects, state-owned enterprises often use the advantages of control and information asymmetry to implement tunneling behavior, which increases the resistance of private enterprises to participation in PPP projects, damages the overall interests of the projects, and is even not conducive to the sustainable development of PPP schemes. Based on the analysis of different forms and the formation mechanism of tunneling, both the implementation condition model and the probability model of tunneling are constructed, through game theory and portfolio model respectively. The results show that the precondition for the tunneling by state-owned enterprises is the control power. The greater the proportion of mining cost to project benefits, the higher the required control power. And the probability of tunneling behavior improves with the decreased mining costs and the increased control power of PPP projects. Moreover, to enhance a better understanding and verify the feasibility and applicability of the models presented earlier in the paper, the application of these models is demonstrated by furnishing a case study-Shuangfengsi Reservoir PPP project through the Monte Carlo simulation. Finally, the paper proposes a few policy recommendations to control of tunneling effectively, including improving the bargaining power of private enterprises, increasing the transparency of project information, strengthening government supervision and attempting to impose synergy across the state-owned enterprises and the whole projects. The findings contribute new insights into the development between PPP schemes and the behavior by the stakeholders, helping curb the tunneling to improve the governance mechanism of PPP projects and promote the sustainable development of PPP schemes.

Key words: PPP projects, state-owned enterprises, tunneling, portfolio model, Monte Carlo simulation

摘要： PPP项目中, 国有企业时常利用控制权优势和信息不对称实施隧道行为, 加大了民营资本进入PPP项目的阻力, 损害了项目整体利益, 不利于PPP模式的健康可持续发展。本文在分析PPP项目中国企隧道行为表现形式和形成机理的基础上, 分别通过博弈论和投资组合模型构建了隧道行为实施条件和发生概率模型。研究结果表明, 国企实施隧道行为需具备基于控制权的先决条件, 挖掘成本相对项目利益的比重越大, 所需控制权越高; 而隧道行为的发生概率随着挖掘成本的降低和控制权的增加而增加。通过蒙特卡洛模拟对河北承德市双峰寺水库PPP项目进行案例分析, 验证了国企隧道行为实施条件和概率模型的可行性和适用性。最终, 分别从提高民企的谈判能力, 增加PPP项目信息透明度, 加强政府监管, 并使国企和项目整体产生利益协同四个方面提出隧道行为治理机制, 保障PPP模式的可持续发展。

关键词: PPP项目, 国有企业, 隧道行为, 投资组合模型, 蒙特卡洛模拟