A Nudge to Credible Information as a Countermeasure to Misinformation: Evidence from Twitter.

This article examines the effectiveness of Twitter's misinformation policy, initiated in May 2019, which nudges users searching for topics prone to health misinformation—specifically vaccines and measles—toward credible information sources rather than employing censorship. Using a quasi-experimental design analyzing 1,468 misinformation articles and over 35,000 related tweets, the study finds that the policy significantly reduces the likelihood that misinformation initiates diffusion on Twitter and decreases the volume of tweets sharing such misinformation. The reduction is primarily driven by decreased sharing among human-like accounts, especially popular and active users, while bot-like accounts remain largely unaffected. These findings suggest that preemptive nudging toward reliable sources can effectively curb misinformation spread without infringing on free speech, offering a potential model for other platforms addressing health misinformation.