Enhancing Resilience through Port Coalitions in Maritime Freight Networks 2020

Reliable port services are key to maritime freight transport system performance. These systems are vulnerable to disasters of anthropogenic or natural cause, which can significantly impact port capacity, handling times and overall system performance. To improve resilience of individual ports, strategies involving capacity sharing and protective cross-port investments through coalition formation are proposed. This collaborative port protection and investment approach to improve individual and system-level port resilience is formulated as an Equilibrium Problem with Equilibrium Constraints. That is, the program is bi-level with multiple players in the upper level and a common liner shipping problem in the lower level. Its solution is obtained at a Nash equilibrium wherein no port stakeholder can achieve better performance by unilaterally changing its investment plan. A Stackelberg equilibrium between upper and lower levels infers that best investment decisions are made given competition between ports and the market’s response to improvements. The benefits of regional coalitions in this co-opetitive (competitive and collaborative) environment in terms of port and system resilience, port- and system-level demand fulfilment rates and return on investment are investigated from multiple perspectives, including the perspectives of shippers, port owners and the larger shipping network. With insights gained through study of the proposed coalition policies, this work aims to facilitate port authorities in making decisions on port capacity expansion, infrastructure investment and forming strategic partnerships. Shipping companies may also take into consideration the ability of a port to provide service under disruption events when choosing which ports to include in their service loops.可靠的港口服务是提升海上货运系统运行效能的核心关键。港口系统易受人为或自然灾害影响，此类灾害会显著削弱港口吞吐能力、延长作业时长，并对整体系统运行效能造成冲击。为提升单个港口的韧性（resilience），本文提出通过组建联盟实现运力共享与跨港保护性投资的策略。该旨在提升单个港口及系统层面港口韧性的协同港口保护与投资方案，被建模为均衡约束均衡问题（Equilibrium Problem with Equilibrium Constraints）。具体而言，该模型为双层规划问题：上层包含多个博弈参与者，下层则对应通用班轮运输问题。其解满足纳什均衡（Nash equilibrium）条件，即任一港口利益相关方均无法通过单方面调整投资计划来获得更优的运行表现。上下层之间的斯塔克尔伯格均衡（Stackelberg equilibrium）则表明，在港口间的竞争与市场对效能提升的响应共同作用下，可得出最优投资决策。本文从托运人、港口所有者以及大型航运网络等多视角出发，对该竞合（competitive and collaborative）环境下区域联盟的效益展开研究，评估维度涵盖港口与系统韧性、港口及系统层面的需求满足率，以及投资回报率。通过对所提出的联盟策略开展研究并获得相关洞见，本研究旨在帮助港口管理部门制定港口扩容、基础设施投资以及组建战略合作伙伴关系的相关决策。航运企业在选择纳入服务航线的港口时，也可将港口在灾害中断场景下的服务保障能力纳入考量因素。