Identification of influential spreaders in complex networks

It is shown that 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), and the most efficient spreaders are those located within the core of the network as identified by the k-shell decomposition analysis.

Abstract

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