Homophily is the tendency of people to associate relatively more with those who are similar to them than with those who are not. In Golub and Jackson (2010a), we introduced degree-weighted homophily (DWH), a new measure of this phenomenon, and showed that it gives a lower bound on the time it...

We examine how the speed of learning and best-response processes depends on homophily: the tendency of agents to associate disproportionately with those having similar traits. When agents' beliefs or behaviors are developed by averaging what they see among their neighbors, then convergence to a...

Gagnon and Goyal (2017) develop an elegant model to understand the interaction between community and markets. One key argument is that, among others, whether markets and social ties are substitutes or complements plays a decisive role: markets undermine social ties in the case of substitutes and...

Although the linear-in-means model is the workhorse model in empirical work on peer effects, its theoretical properties are understudied. In this study, we develop a social-norm model that provides a microfoundation of the linear-in-means model and investigate its properties. We show that...

We examine friendships and study partnerships among university students over several years. At the aggregate level, connections increase over time, but homophily on gender and ethnicity is relatively constant across time, university residences, and different network layers. At the individual...

There is growing evidence that face-to-face interaction is declining in many countries, exacerbating the phenomenon of social isolation. On the other hand, social interaction through online networking sites is steeply rising. To analyze these societal dynamics, we have built an evolutionary game...

This paper studies the impact of collaboration on research output. First, we build a micro founded model for scientific knowledge production, where collaboration between researchers is represented by a bipartite network. The equilibrium of the game incorporates both the complementarity effect...

In this article, we analyze the dynamic competition between two platform firms (A&B) in two-sided markets with network externalities. In Period 1, platform A or B wins the contest in a first stage and can serve the two-sided market monopolistically in a second stage. In Period 2, the two...