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.可靠的港口服务是海上货运系统（maritime freight transport system）性能优化的核心支撑。此类系统易受人为或自然灾害冲击，此类灾害可显著削弱港口吞吐能力、延长货物作业时长，并对系统整体性能产生负面影响。为提升单个港口的韧性（resilience），本研究提出通过组建联盟实现运力共享与跨港保护性投资的相关策略。这种旨在提升单个港口与系统层面港口韧性的协同港口防护与投资策略，被建模为均衡约束均衡问题（Equilibrium Problem with Equilibrium Constraints）。具体而言，该模型为双层规划模型：上层包含多个博弈参与者，下层则对应典型的班轮运输（liner shipping）问题。该模型的解可通过纳什均衡（Nash equilibrium）求得，此时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绩效表现。上层与下层之间的斯塔克尔伯格均衡（Stackelberg equilibrium）表明，在港口间竞争与市场对优化措施的响应共同作用下，可得出最优投资决策。本研究从托运人、港口所有者以及大型航运网络等多个视角，对该竞合（co-opetitive，即竞争与协同并存）环境下的区域联盟所带来的收益展开了探究，具体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等维度。通过对所提出的联盟策略开展研究并获取相关洞见，本研究旨在助力港口管理当局制定港口扩容、基础设施投资以及组建战略合作伙伴关系等决策。航运企业在选择纳入其服务航线网络的港口时，也可考量港口在遭遇中断事件时的服务保障能力。