News Credibility Labels Have Limited Average Effects on News Diet Quality and Fail to Reduce Misperceptions

On average, source credibility labels don’t change whether someone reads low-quality news sources — but it does appear to improve the news diet quality of the heaviest consumers of misinformation.


As the primary arena for viral misinformation shifts toward transnational threats, the search continues for scalable countermeasures compatible with principles of transparency and free expression. We conducted a randomized field experiment evaluating the impact of source credibility labels embedded in users’ social feeds and search results pages. By combining representative surveys (n = 3337) and digital trace data (n = 968) from a subset of respondents, we provide a rare ecologically valid test of such an intervention on both attitudes and behavior. On average across the sample, we are unable to detect changes in real-world consumption of news from low-quality sources after 3 weeks. We can also rule out small effects on perceived accuracy of popular misinformation spread about the Black Lives Matter movement and coronavirus disease 2019. However, we present suggestive evidence of a substantively meaningful increase in news diet quality among the heaviest consumers of misinformation. We discuss the implications of our findings for scholars and practitioners.


The internet and social media have drastically reduced the cost of disseminating information. But it’s also made it easier than ever to spread misinformation, which research suggests can increase belief in misperceptions, heighten cynicism toward politics, lower trust in media, and increase affective polarization. There have been a number of proposed interventions to mitigate these issues and reduce exposure to misleading information, including changing algorithms to downrank disinformation, introducing warnings and labels, and boosting digital literacy skills.


We evaluated the impact of one often-recommended intervention, “source credibility labels.” In an online field experiment conducted in May and June 2020, we encouraged a random sample of more than 3,000 online participants to install the NewsGuard browser extension, which embeds source-level indicators of news reliability into users’ search engine results pages, social feeds, and visited URLs. We also collected anonymized digital trace data to characterize the quality of news consumption of a subset of approximately 1,000 participants. We tested whether in-feed source reliability labels can shift news consumption from unreliable to more reliable sources, increase trust in mainstream media and reliable sources, and/or mitigate political polarization and cynicism. We also explored whether any of the identified effects are greater among subgroups found in prior research to more frequently engage with online misinformation.


We found that, on average, in-browser credibility labels did not measurably shift online consumption from unreliable to more reliable sources, failed to significantly alter misperceptions of widely circulated inaccurate claims about COVID-19 and the Black Lives Matter movement, and did not alter trust in the media generally. However, there was a noticeable improvement in the overall credibility of news sources visited by those who began the study with the lowest news diet quality, suggesting that interventions designed to counteract misinformation should target those who consume the most low quality news.