Revisiting urban hierarchy and specialization from a maritime perspective

Abstract

Port-city relationships have attracted paramount attention from a variety of scientific disciplines for several decades, such as geography, history, planning, regional science, sociology, and economics to name but a few. Yet, the extent to which maritime traffic specialization obeys the same spatial distribution than other economic activities remains underexplored today. This article tackles this lacunae head on by proposing an empirical analysis of the way vessel tonnage per main categories of flows (e.g. containers, bulks, passengers) coincides with the demographic size of the world's coastal and inland city-regions, using novel data on global inter-port vessel movements and harmonized population data over the period 1977-2008. Our main results confirm that such traffic is far from being randomly distributed, as its volume, value, and diversity concentrate at the top of the urban hierarchy. This confirms both classic and recent works on scaling laws in urban systems, the latter being either more national in scope or more focused on immaterial rather than material flows. Lastly, we focus on European port cities in more detail including centrality indicators based on their position in the global maritime and sea-land network. This research motivates the need to further integrate physical connectivity into the study of cities and their development mechanisms.

Port specialization and connectivity in the global maritime network

“…At the European level, Ducruet et al (2010) found a significant correlation between commodity diversity and traffic size, albeit many exceptions. Numerous small and medium-sized ports situated at the periphery and/or on islands could reach a comparable traffic diversity than Rotterdam and other large mainland gateways, thanks to their captive hinterland, protected from competition (see also Ducruet, 2020 for a global perspective).…”

The mutual specialization of port and urban functions: The case of France

“…), and in a comparative manner, to check whether larger cities handle more diversified traffic (cf. Ducruet, 2020a; Ducruet et al, 2010), and whether larger traffic occurs in more diversified economies.…”

Coupled connectivity in the global complex network: the case of United Kingdom (1880–1925)

“…According to Pumain (2006) and Pumain et al (2009), the "largest cities became larger because they were successful in adopting many successive innovations [while] the most advanced technologies concentrate in largest cities". In terms of maritime flows and networks, there is a path-and place-dependent process by which the most populated cities are the most diversified in terms of traffic type Ducruet 2020).…”