The worldwide air transportation network: Anomalous centrality, community structure, and cities' global roles

TLDR

The worldwide air transportation network is a critical infrastructure that profoundly influences local, national, and international economies. The study analyzes the global structure of the worldwide air transportation network. Findings show that the network is a scale‑free small‑world network, yet its most connected cities are not the most central due to a multi‑community structure influenced by geopolitical factors, and city roles can be defined by their inter‑ and intra‑community connections, providing scale‑specific network representations.

Abstract

We analyze the global structure of the world-wide air transportation network, a critical infrastructure with an enormous impact on local, national, and international economies. We find that the world-wide air transportation network is a scale-free small-world network. In contrast to the prediction of scale-free network models, however, we find that the most connected cities are not necessarily the most central, resulting in anomalous values of the centrality. We demonstrate that these anomalies arise because of the multi-community structure of the network. We identify the communities in the air transportation network and show that the community structure cannot be explained solely based on geographical constraints, and that geo-political considerations have to be taken into account. We identify each city's global role based on its pattern of inter- and intra-community connections, which enables us to obtain scale-specific representations of the network.