Analyses of treatments, experiments, policies, and observational data, are confounded when people's treatment outcomes and/or participation decisions are influenced by those of their friends and acquaintances. This invalidates standard matching techniques as estimation tools. For instance, the...

We study how communication platforms, or a society more generally, can improve social learning without censoring or fact-checking messages. We analyze learning as a function of social network depth (how many times information is relayed) and breadth (the number of relay chains accessed). Noise...

We study the consequences of job markets' heavy reliance on referrals. Referrals screen candidates and lead to better matches and increased productivity, but disadvantage job-seekers who have few or no connections to employed workers, leading to increased inequality. Coupled with homophily,...

We analyze how interdependencies in financial networks can lead to self-fulfilling insolvencies and multiple possible equilibrium outcomes. We show that multiplicity arises if and only if there exists a certain type of dependency cycle in the network, and characterize banks' solvency in any...

We use the universe of USPTO data on patents and inventors from 1976 to 2019 to look at the dynamics of coauthorship on patents and its relationship with competition. First, we find an inverted-U relationship between competition and the growth in coauthorship: the number of new collaborators on...

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...

We study how advances in labor-substituting (automation) technologies affect production networks. Labor-substituting advances lower the wages of substitutable workers relative to non-substitutable workers, affecting employment in the entire economy, well beyond the production chains adopting the...

When people coordinate their behaviors with their friends---choosing whether to adopt a new technology, to protest against a government, to attend university, etc.---divisions within a social network can result in people adopting different conventions of behavior in different parts of the...

I discuss economic and social sources of inequality and elaborate on the role of social networks in inequality, economic immobility, and economic inefficiencies. The lens of social networks clarifies how the entanglement of people's information, opportunities, and behaviors with those of their...

We develop a new class of random-graph models for the statistical estimation of network formation---subgraph generated models (SUGMs)---that allow for substantial correlation in links. Various subgraphs (e.g., links, triangles, cliques, stars) are generated and their union results in a network....