Individuals derive benefits from their connections, but these may, at the same time, transmit external threats. Individuals therefore invest in security to protect themselves. However, the incentives to invest in security depend on their network exposures. We study the problem of designing a...

Infrastructure networks -- in communication and transport -- are a key feature of an economy. The functionality of these networks depends on the connectivity and sizes of different components. However, these networks face a variety of threats ranging from natural disasters to intelligent attacks...

A recurring theme in the study of society is the concentration of influence and power that is driven through unequal membership of groups and associations. In some instances, these bodies constitute a small world while in others they are fragmented into distinct cliques. This paper presents a...

Modern economies rely heavily on their infrastructure networks. These networks face threats ranging from natural disasters to human attacks. As networks are pervasive, the investments needed to protect them are very large; this motivates the study of targeted defense. What are the 'key' nodes to...

Modern economies rely heavily on their infrastructure networks. These networks face threats ranging from natural disasters to human attacks. As networks are pervasive, the investments needed to protect them are very large; this motivates the study of targeted defence. What are the 'key' nodes to...