Global port vulnerability and sustainability in a risky world: empirical evidence from congestion, natural disasters, and geopolitical tensions

Abstract

Maritime transport is considered the backbone of international trade and the global economy, with ports worldwide handling 80% of global trade by volume and 70% of global trade by value. Meanwhile, ports are vulnerable to both natural and human-induced disruptions, which can severely impact the global supply chains, leading to delays in the delivery of goods, increased transportation costs, and shortages of essential commodities. This study aims to investigate the disruptions that threaten port operations and the underlying mechanisms by using high-frequency global vessel data, which are essential for developing effective counter-measures to mitigate the adverse impact on international trade and economic stability. The first chapter explores congestion internalization at ports, with a particular analysis of the distinctive aspect of berthing priority and its impact on congestion. To address concerns related to endogeneity, the empirical analysis employs an instrumental variable approach. The results reveal that higher market concentration decreases port delays, as dominant shipping lines may internalize congestion. However, the provision of berthing priority in seaports might exacerbate delays at terminals and diminish shipping lines' motivation to mitigate congestion internally. The second chapter assesses port resilience under climate-related disasters. A port vulnerability index is developed based on the duration each port takes to rebound to its pre-disaster level of port calls. Subsequent analyses show that port vulnerability is inversely associated with factors at the hinterland, port interface, and seaside levels, including hinterland industrial diversity, port size, and port connectivity within the global liner shipping network. The third chapter evaluates how geopolitical tensions influence carbon emissions at the port level. Leveraging a SYS-GMM framework, the findings indicate that rising geopolitical risks increase carbon emissions by disrupting vessel arrivals and reducing berthing efficiency. Larger-vessel ports are more exposed to such shocks, while ports with high carrier concentration display greater operational resilience due to better coordination under uncertainty. These findings provide novel insights into the sustainability of international trade under internal and external risks and offer potential avenues for enhancing trade resilience.