Multiscale core-periphery structure in a global liner shipping network

TL;DR

This paper analyzes the global liner shipping network as a graph, revealing a multiscale core-periphery structure that highlights key ports and their roles in international maritime trade.

Contribution

It introduces a novel algorithm for detecting multiscale core-periphery structures in bipartite-derived networks, accounting for the network's bipartite origin.

Findings

Most ports are core ports, not peripheral.

Certain countries' ports form a global core-periphery pair.

The core-periphery structure varies across different scales.

Abstract

Maritime transport accounts for a majority of trades in volume, of which 70% in value is carried by container ships that transit regular routes on fixed schedules in the ocean. In the present paper, we analyse a data set of global liner shipping as a network of ports. In particular, we construct the network of the ports as the one-mode projection of a bipartite network composed of ports and ship routes. Like other transportation networks, global liner shipping networks may have core-periphery structure, where a core and a periphery are groups of densely and sparsely interconnected nodes, respectively. Core-periphery structure may have practical implications for understanding the robustness, efficiency and uneven development of international transportation systems. We develop an algorithm to detect core-periphery pairs in a network, which allows one to find core and peripheral nodes on different scales and uses a configuration model that accounts for the fact that the network is obtained by the one-mode projection of a bipartite network. We also found that most ports are core (as opposed to peripheral) ports and that ports in some countries in Europe, America and Asia belong to a global core-periphery pair across different scales, whereas ports in other countries do not.