We use anonymized and aggregated data from Facebook to explore the spatial structure of social networks in the New York metro area. We highlight the importance of transportation infrastructure in shaping urban social networks by showingthat travel time and travel costs are substantially stronger...

We use aggregated data from Facebook to show that COVID-19 was more likely to spread between regions with stronger social network connections. Areas with more social ties to two early COVID-19 "hotspots" (Westchester County, NY, in the U.S. and Lodi province in Italy) generally had more...

We model social media as collections of users producing and consuming content. Users value consuming content, but doing so uses up their scarce attention, and hence they prefer content produced by more able users. Users also value receiving attention, creating the incentive to attract an...

In this paper, we investigate political communications in social networks characterized both by homophily-a tendency to associate with similar individuals-and group size. To generate testable hypotheses, we develop a simple theory of information diffusion in social networks with homophily and...

We study how job-seekers share information about jobs within their social network, and its implications for firms. We randomly increase the amount of competition for a job and find that job-seekers are: (i) less likely to share information about the job with their peers; and (ii) choose to...

We document that the recent house price experiences within an individual's social network affect her perceptions of the attractiveness of property investments, and through this channel have large effects on her housing market activity. Our data combine anonymized social network information from...

In this paper, we study the changes in transaction costs from the introduction of the Internet in transactions between firms (i.e., business-to-business (B2B) e-commerce). We begin with a conceptual framework to organize the changes in transaction costs that are likely to result when a...

Digital platforms are not only match-making intermediaries but also establish internal rules that govern all users in their ecosystems. To better understand the governing role of platforms, we study two Airbnb pro-guest rules that pertain to guest and host cancellations, using data on Airbnb and...

Digital goods can generate large benefits for consumers, but these benefits are largely unmeasured in the national accounts, including GDP and productivity. In this paper, we measure welfare gains from 10 popular digital goods across 13 countries by conducting large-scale incentivized online...

Individuals might experience negative utility from not consuming a popular product. For example, being inactive on social media can lead to social exclusion or not owning luxury brands can be associated with having a low social status. We show that, in the presence of such spillovers to...