Here’s the abstract for Karsten Müller and Carlo Schwarz’s Making America Hate Again? Twitter and Hate Crime Under Trump (Mar. 28, 2018):
Social media has come under increasing scrutiny for reinforcing people’s pre-existing viewpoints which, it is argued, can create information “echo chambers”. We investigate whether such reinforcement motivates real-life action, with a focus on hate crimes in the United States. We show that the rise in anti-Muslim hate crimes in the US since Donald Trump’s presidential campaign has been concentrated in counties with high Twitter usage. Consistent with a role for social media, Trump’s Tweets on Islam-related topics are highly correlated with anti-Muslim hate crime after, but not before the start of his presidential campaign, and are uncorrelated with other types of hate crimes. These patterns stand out in historical comparison: counties with many Twitter users today did not consistently experience more anti-Muslim hate crimes during previous presidencies.