Ports, Technology and Inter-City Trade: The Economics and Geopolitics of Evolving Maritime Transport Networks

Maritime transport remains the backbone of global trade, yet the port and shipping network that carries it has been transformed by containerization and related technological advances. Drawing on newly available granular data---digitized historical shipping records, georeferenced ship movements, and shipment-level routing information---we present five stylized facts on the structure and evolution of the maritime network. Global shipping activity is highly concentrated among a changing lineup of dominant top ports even as lower-ranked ports disperse, while state-owned Chinese port terminal operators increasingly account for these global volumes, boosting overall port operations while delivering efficiency gains mostly to Chinese vessels. We use these facts to organize a synthesis of a fast-growing literature: containerization reshaped which port cities could expand, reinforced hub-and-spoke concentration that yields large but localized welfare gains, embedded ports in multimodal networks that amplify the returns to infrastructure, and generated market power, congestion, and environmental costs. Together, this evidence shows how evolving maritime technologies simultaneously deepen global integration and heighten the economic and geopolitical importance of critical nodes in the transport network---and of who controls them.