  What makes economic and ecological networks so unlike other highly skewed
networks in their tendency toward turbulence and collapse? Here, we explore the
consequences of a defining feature of these networks: their nodes are tied
together by flow. We show that flow networks tend to the power law degree
distribution (PLDD) due to a self-reinforcing process involving position within
the global network structure, and thus present the first random graph model for
PLDDs that does not depend on a rich-get-richer function of nodal degree. We
also show that in contrast to non-flow networks, PLDD flow networks are
dramatically more vulnerable to catastrophic failure than non-PLDD flow
networks, a finding with potential explanatory power in our age of resource-
and financial-interdependence and turbulence.
