How Many People Live in Political Bubbles on Social Media? Evidence From Linked Survey and Twitter Data

A major point of debate in the study of the Internet and politics is the extent to which social media platforms encourage citizens to inhabit online "bubbles" or "echo chambers," exposed primarily to ideologically congenial political information. To investigate this question, we link a representative survey of Americans with data from respondents' public Twitter accounts (N = 1,496). We then quantify the ideological distributions of users' online political and media environments by merging validated estimates of user ideology with the full set of accounts followed by our survey respondents (N = 642,345) and the available tweets posted by those accounts (N similar to 1.2 billion). We study the extent to which liberals and conservatives encounter counter-attitudinal messages in two distinct ways: (a) by the accounts they follow and (b) by the tweets they receive from those accounts, either directly or indirectly (via retweets). More than a third of respondents do not follow any media sources, but among those who do, we find a substantial amount of overlap (51%) in the ideological distributions of accounts followed by users on opposite ends of the political spectrum. At the same time, however, we find asymmetries in individuals' willingness to venture into cross-cutting spaces, with conservatives more likely to follow media and political accounts classified as left-leaning than the reverse. Finally, we argue that such choices are likely tempered by online news watching behavior.