One definition of social capital is the "networks of relationships among people who live and work in a particular society, enabling that society to function effectively". This definition of social capital highlights two key features. First, it refers to connections between people, shifting our...

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...

Delinquents are embedded in a network of relationships. Social ties among delinquents are modeled by means of a graph where delinquents compete for a booty and benefit from local interactions with their neighbors. Each delinquent decides in a non-cooperative way how much delinquency effort he...

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...

This paper studies how birth town migration networks affected long-run location decisions during historical U.S. migration episodes. We develop a new method to estimate the strength of migration networks for each receiving and sending location. Our estimates imply that when one randomly chosen...

This paper analyzes the role of networks in the spatial diffusion of local economic shocks in Africa. We show that road and ethnic connectivity are particularly important factors for diffusing economic spillovers over longer distances. We then determine the key players, i.e., which districts are...

In this paper we examine the education and occupation mismatch for Hispanics in the US using a novel objective continuous mismatch index and explore the role of immigrants' social networks on this mismatch. We explore whether having a larger social network helps Hispanics in finding jobs that...

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...

Can large-scale peer interaction foster entrepreneurship and innovation? We conducted an RCT involving almost 5,000 entrepreneurs from 49 African countries. All were enrolled in an online business course, and the treatment involved random assignment to either face-to-face or virtual...