Many types of economic and social activities involve significant behavioral complementarities (peer effects) with neighbors in the social network. The same activities often exert externalities that cumulate in "stocks" affecting agents' welfare and incentives. For instance, smoking is subject to...

Publicly traded firms in the U.S. typically determine C.E.O. compensation by benchmarking the pay of their C.E.O.s against the pay of C.E.O.s in “peer” firms. The naming of particular peer companies by individual firms constitutes a supra-firm relational structure (network) in which an...

This paper presents a simple model of strategic network formation with local complementarities in effort levels and positive local externalities for a general class of payoff functions. Results are obtained for one-sided and two-sided link creation. In both cases (pairwise) Nash equilibrium...

We survey the recent, fast-growing literature on peer effects in networks. An important recurring theme is that the causal identification of peer effects depends on the structure of the network itself. In the absence of correlated effects, the reflection problem is generally solved by network...