The structure of online social networks and social movements: Evidence from the Black Lives Matter protests

Abstract

This paper documents that online social networks – Facebook in particular – can facilitate the spread of social movements across space and time. Focusing on the largest protest movement in recent history, the wave of Black Lives Matter protests sparked by the killing of George Floyd on 25 May 2020, we show that protests are more likely to spill over between US counties when they are more closely connected within the Facebook network. To identify causal effects, we develop an instrumental variable approach that exploits local Facebook outages as a source of exogenous variation in the structure of the online network.