  We investigate cascades in networks consisting of strategic agents with
interdependent security. We assume that the strategic agents have choices
between i) investing in protecting themselves, ii) purchasing insurance to
transfer (some) risks, and iii) taking no actions. Using a population game
model, we study how various system parameters, such as node degrees, infection
propagation rate, and the probability with which infected nodes transmit
infection to neighbors, affect nodes' choices at Nash equilibria and the
resultant price of anarchy/stability. In addition, we examine how the
probability that a single infected node can spread the infection to a
significant portion of the entire network, called cascade probability, behaves
with respect to system parameters. In particular, we demonstrate that, at least
for some parameter regimes, the cascade probability increases with the average
degree of nodes.
