Community-based fact-checking reduces the spread of misleading posts on social media

TL;DR

This large-scale empirical study demonstrates that community-based fact-checking significantly reduces the spread of misinformation on social media, though it may be less effective in early viral stages.

Contribution

The paper provides causal evidence that community notes decrease misinformation spread and increase user deletion of misleading posts, highlighting their impact at scale.

Findings

Community notes reduce misinformation spread by 62%.

They increase the likelihood of users deleting misleading posts by 103%.

Community notes may be slow to intervene in early viral diffusion.

Abstract

Community-based fact-checking is a promising approach to verify social media content and correct misleading posts at scale. Yet, causal evidence regarding its effectiveness in reducing the spread of misinformation on social media is missing. Here, we performed a large-scale empirical study to analyze whether community notes reduce the spread of misleading posts on X. Using a Difference-in-Differences design and repost time series data for N=237,677 (community fact-checked) cascades that had been reposted more than 431 million times, we found that exposing users to community notes reduced the spread of misleading posts by, on average, 62.0%. Furthermore, community notes increased the odds that users delete their misleading posts by 103.4%. However, our findings also suggest that community notes might be too slow to intervene in the early (and most viral) stage of the diffusion. Our work offers important implications to enhance the effectiveness of community-based fact-checking approaches on social media.