Trade dynamics of the global dry bulk shipping network
利用2015至2023年微观贸易流数据，分析全球干散货航运网络及其煤炭、谷物、铁矿石子网络的结构、韧性与脆弱性，发现网络高度集中于少数关键出口港，且外部冲击的影响因商品而异。
The primary objective of this study is to determine how global shocks and commodity-specific geographical factors interact to shape the structure, resilience, and vulnerability of the dry bulk shipping network. To do so, we examine the global dry bulk shipping network and its coal, grain, and iron ore sub-networks from 2015 to 2023 using micro-level trade flow data. We find that these networks are highly concentrated around a small number of key export ports, with heavy-tailed degree distributions and strong core-periphery structures. However, the impact of external shocks is sharply commodity-specific: the COVID-19 pandemic triggered a major reorganisation of coal trade communities, while the war in Ukraine fragmented the grain network and drastically reduced Ukraine’s exports. In contrast, iron ore trade patterns remained relatively stable during the same period. Small-world features are present mainly within the densely interconnected core of each commodity network, where bi-directional trades are observed, while most peripheral ports function as either importers or exporters only. These findings clarify how the interplay of geography, trade imbalance, and global disruptions shapes network structure and resilience, offering insights for supply chain risk management in maritime logistics.