We present a dynamic model of network formation where nodes find other nodes with whom to form links in two ways: some are found uniformly at random, while others are found by searching locally through the current structure of the network (e.g., meeting friends of friends). This combination of...

We examine a simple economic model of network formation where agents benefit from indirect relationships. We show that small-world features-short path lengths between nodes together with highly clustered link structures-necessarily emerge for a wide set of parameters. (JEL: D85, A14, C72)...

We consider the spread of a harmful state through a population that is divided into two groups. The groups interact with each other to an extent that is parameterized, capturing the full spectrum from perfectly positive to perfectly negative assortativity. We first consider a central planner who...

We consider the spread of a harmful state through a population divided into two groups. Interaction patterns capture the full spectrum of assortativity possibilities. We show that a central planner who aims for eradication optimally either divides equally the resources across groups, or...

We report experimental results from long sequences of decisions in environments that are theoretically prone to severe information cascades. Observed behaviour is much different—information cascades are ephemeral. We study the implications of a theoretical model based on quantal response...