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 cummulate in 'stocks' affecting agents' welfare and incentives. For instance, smoking is subject...

We study network formation where nodes are born sequentially and form links with previously born nodes. Connections are formed through a combination of random meetings and through search, as in Jackson and Rogers (2007). A newborn's random meetings of existing nodes are type-dependent and the...

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...

Many Social Interactions display either or both of the following well documented phenomena. People tend to interact with similar others (homophily). And they tend to treat others more favorably if they are perceived to share the same identity (in-group bias). While both phenomena involve some...