中文摘要：

通过对多个国外典型项目案例的研究，对比分析了公共基础设施BOT项目弹性特许期决策模式选择的现状，提出单一收益约束模式、多重收益约束模式和中间谈判模式三种弹性特许期决策模式，并从决策依据、特许期长度、激励约束作用、监管难度和风险分担能力五个方面对特许期决策模式加以对比分析。研究结果表明，三种弹性特许期决策模式均以实际收益为决策依据，但决策标准不同；特许期长度均弹性变化，但特许期终止原则各不一样；在三种弹性特许期决策模式中，多重收益约束模式的激励约束作用和风险分担能力最强，单一收益约束模式的监管难度最高；与固定特许期决策模式相比，采用弹性特许期决策模式有利于实现项目干系人的风险分担与社会公平。

英文摘要：

Based on a multi-case study on foreign typical projects, this work comparatively analyzes the current status of the decision mode selection for flexible concession term of BOT projects in public infrastructure. Three decision modes for flexible concession term, namely single revenue constraint mode, multiple revenue constraints mode and negotiation mode, are originally proposed. Then the three modes are comparatively elaborated from the perspective of decision basis, the length of concession term, the functions of incentives and constraints, supervision difficulty and risk allocation, respectively. The results show that three decision modes for flexible concession term are all based on the actual revenue and the length of each concession term is elastically changed, but with different decision criteria and termination principles. Among the three decision modes for flexible concession term, the incentive and restraint roles as well as the ability of risk allocation for the multiple re＇venue constraints mode are the strongest, while the supcrvision for the single revenue constraint mode is the most difficult. In addition, compared with the decision mode for fixed concession term, the flexible concession term is more beneficial to achieve the risk allocation among the stakeholders and the social equity.