We use anonymized data from Facebook to construct a new measure of the pairwise social connectedness between 180 countries and 332 European regions. We find that two countries trade more with each other when they are more socially connected and when they share social connections with a similar...

We use aggregated data from Facebook to study the structure of social networks across European regions. Social connectedness declines strongly in geographic distance and at country borders. Historical borders and unions — such as the Austro-Hungarian Empire, Czechoslovakia, and East/West...

The European higher education landscape has become increasingly integrated causing competition among universities that is no longer bound to national borders. In view of this development, the present paper investigates the relative efficiency of 450 European universities between 2011 and 2014....

We use anonymized and aggregated data from Facebook to show that areas with stronger social ties to two early COVID-19 "hotspots" (Westchester County, NY, in the U.S. and Lodi province in Italy) generally have more confirmed COVID-19 cases as of March 30, 2020. These relationships hold after...

Through social media, politicians can personalize their campaigns and target specific groups of voters with an unprecedented precision. We assess the effects of such political micro-targeting by exploiting daily advertising prices on Facebook during the 2016 US presidential campaign. We measure...

We analyze the effect and welfare implications of taxing multinational digital platforms on the global online advertising market. Using a novel dataset on advertising prices and product preferences of users from Facebook in OECD countries, jointly with international trade data, we show that an...

We study peer influence in an online social network on a platform where consumers purchase music albums. They can follow their peers and become informed about their consumption choices. In particular, we are interested in how this affects consumers’ exploration of new music that exhibits...

This paper provides the first causal evidence that hostile activities online lead to physical violence. Given the recently documented relationship between pollution and social media, I exploit exogenous variation in local air quality as the first step to instrument for online aggression. In an...

This paper studies how social relationships between managers and employees affect relational incentive contracts. To this end we develop a simple dynamic principal-agent model where both players may have feelings of altruism or spite toward each other. The contract may contain two types of...