The Partisan Effects of Social Media Bans

Abstract

What happens to information environments when democracies ban social media

platforms? While a large literature examines information control under authoritarianism,

democratic governments have increasingly intervened in major online platforms. We

study a prominent case: Brazil’s 2024 national ban on the social media platform X. Using

an event-study design, we estimate the causal effects of the ban and examine how partisan

identity shaped responses. Drawing on a large sample of politically engaged users and

ideal-point estimates of ideology, we find strong partisan asymmetries. Conservative

users not aligned with the government were more likely to circumvent the ban, and

right-leaning news domains became markedly more prevalent on the platform. We

describe this dynamic as a “sorting ratchet”: the ban segmented the digital public

sphere along partisan lines, with effects that persisted even after restrictions were lifted.

Platform bans in democratic settings may therefore deepen polarization and durably

reshape information environments