基于Moran过程的PPP项目承包商机会主义行为演化动态

在PPP项目中，由于政府部门和承包商的目标不一致以及信息不对称等原因的存在，使得在其全寿命周期过程中，承包商的机会主义行为屡见不鲜。本文基于随机演化博弈理论，建构基于Moran过程的博弈模型，旨在探讨推动PPP项目承包商不采取机会主义行为策略的有利条件。研究表明，承包商数目不断扩大，通过降低承包商之间的举报成本，增大惩处力度，可使降低机会主义行为发生概率的效果显著。进一步，借助数值算例，对研究结果进行验证并给出相应的管理对策。

Evolution Dynamics of Opportunistic Behavior of PPP Project Contractors Baesd on Moran Process

In the PPP project, due to the goal inconsistency and information asymmetry of the government department and contractor, the contractor''s opportunistic behavior is common during the whole life cycle. Based on the stochastic evolutionary game theory, this paper constructs a game model with the Moran process to study the evolutionary dynamics of different behavior strategies. The purpose is to explore the favorable conditions for promoting PPP project contractors not to adopt opportunistic behavior strategy. Studies have shown that the occurrence probability of contractor''s opportunistic behavior can be lowered by increasing of the number of contractors or reducing the reporting cost between contractors and increasing the punishment cost of opportunistic behavior. Further, results are verified and management countermeasures are demonstrated with the numerical examples.