We study Facebook networks at 40 American universities, with focus on the comparison of their degree distributions and mechanism governing their evolution. We find that the heterogeneity indexes of these networks are all small compared with scale-free networks, and different from real-world...

We discuss a special Pólya lattice model to study cascading failures of firms in a simple industrial economy. In particular, every firm is represented by a Pólya-like urn, whose reinforcement is function of time, of the neighboring urns and their compositions, and of a random variable...

Mobility of humans plays an important role in shaping the performance of various services in mobile and location dependent networks. In this paper, we amalgamate and summarize the parameters reported in various trace analyses, and explore the inter-dependencies among the parameters using a...

Power law behavior is an emerging property of many economic models. In this paper we emphasize the fact that power law distributions are persistent but not time invariant. In fact, the scale and shape of the firms' size distribution fluctuate over time. In particular, on a log–log space, both...

A link in a supplier–customer network is usually a creditor–debtor relationship. If a firm goes into a state of financial insolvency or bankruptcy, then firms on its upstream are affected secondarily along the links. By using 10-year data from recent data on bankruptcy in Japan, we show that...