The Effect of Anonymity in Social Media on Fake News Sharing

<jats:p>We study how anonymity affects fake-news sharing on social media using a natural experimenton Flashback, a large Swedish online discussion forum. In 2014, journalists obtainedinformation that allowed them to identify users registered before March 2007, sharply increasingthese users’ risk of public exposure while leaving later registrants unaffected. Usinga difference-in-differences design on 1.98 million posts, we find that exposed users reducereferences to fake-news sites by about one-quarter of the mean. The effect is concentratedin immigration and domestic-politics discussions and does not extend to legitimate newssources, suggesting that accountability reduces misinformation without reducing news sharingmore broadly.</jats:p>