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 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 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...

In contrast to what several papers have argued recently, we show that firm heterogeneity fosters agglomeration of economic activity. If firms are more similar with respect to their total factor productivity, each company faces a lower propensity to export. This renders the home market more...

This paper develops a static model of endogenous task-based technical progress to study how factor scarcity induces technological progress and changes in factor prices. The equilibrium technology is multi-dimensional and not strongly factor-saving in the sense of Acemoglu (2010). Nevertheless,...

Many of the exports of developing countries are channeled through global value chains (GVCs), which also act as conduits for new technologies. However, new capabilities and productive employment remain limited so far to a tiny sliver of globally integrated firms. GVCs and new technologies...