Hierarchical clustering and consensus in trust networks

We apply recent developments in clustering theory of asymmetric networks to study the equilibrium configurations of consensus dynamics in trust networks. We show that reciprocal clustering characterizes the equilibrium opinions of mutual trust dynamics. That is, clusters in the reciprocal dendrogram correspond to different equilibrium opinions of mutual trust consensus for varying trust thresholds. Moreover, for unidirectional trust dynamics, we show that aggregating nonreciprocal clusters into single nodes does not modify reachability of global consensus, thus, simplifying the consensus analysis of large networks.