We discuss social network analysis from the perspective of economics. We organize the presentation around the theme of externalities: the effects that one's behavior has on others' welfare. Externalities underlie the interdependencies that make networks interesting to social scientists. We...

We survey the literature on social networks by putting together the economics, sociological and physics/applied mathematics approaches, showing their similarities and differences. We expose, in particular, the two main ways of modeling network formation. While the physics/applied mathematics...