Date Added: Jun 2010
Hierarchies occur widely in evolving self-organizing ecological, biological, technological and social networks, but detecting and comparing hierarchies is difficult. Here the authors present a metric and technique to quantitatively assess the extent to which self-organizing directed networks exhibit a flow hierarchy. Flow hierarchy is a commonly observed but theoretically overlooked form of hierarchy in networks. They show that the ecological, neurobiological, economic and information processing networks are generally more hierarchical than their comparable random networks.