Identification of influential spreaders in complex networks

TL;DR

This paper challenges traditional notions of influential spreaders in networks, showing that core network positions identified by k-shell decomposition are more effective for spreading than highly connected nodes, with implications for optimizing dissemination strategies.

Contribution

The study introduces the k-shell decomposition as a superior method for identifying influential spreaders and analyzes the impact of multiple spreaders and network structure on spreading efficiency.

Findings

Core network nodes are more influential than hubs.

Distance between multiple spreaders affects spreading efficiency.

Infections persist in high k-shell layers even when hubs are ineffective.

Abstract

Networks portray a multitude of interactions through which people meet, ideas are spread, and infectious diseases propagate within a society. Identifying the most efficient "spreaders" in a network is an important step to optimize the use of available resources and ensure the more efficient spread of information. Here we show that, in contrast to common belief, the most influential spreaders in a social network do not correspond to the best connected people or to the most central people (high betweenness centrality). Instead, we find: (i) The most efficient spreaders are those located within the core of the network as identified by the k-shell decomposition analysis. (ii) When multiple spreaders are considered simultaneously, the distance between them becomes the crucial parameter that determines the extend of the spreading. Furthermore, we find that-- in the case of infections that do not confer immunity on recovered individuals-- the infection persists in the high k-shell layers of the network under conditions where hubs may not be able to preserve the infection. Our analysis provides a plausible route for an optimal design of efficient dissemination strategies.