Fact-Checking and Misinformation: Evidence from the Market Leader

What are the dynamic effects of fact-checking on the behavior of those who circulate misinformation and on the spread of false news? In this paper, we provide causal evidence on these questions, building on a unique partnership with the Agence France Presse (AFP), the world’s largest fact-checking organization and a partner of Facebook’s Third-Party Fact-Checking Program. Over an 18-month period (December 2021-June 2023), we collected information on the stories proposed by fact-checkers during the daily editorial meetings, some of which were ultimately fact-checked while others, despite being ex ante “similar”, were left aside. Using two complementary Difference-in-Differences approaches, one at the story level and the other at the post level (within fact-checked stories), we show that fact-checking reduces the circulation of misinformation on Facebook by approximately 8%, an effect driven entirely by stories rated as “False.” Furthermore, we provide evidence of behavioral responses: the publication of a fact-check more than doubles the deletion of posts in the fact-checked stories, and users whose posts appear in fact-checked stories become less likely to share misinformation in the future. While our results clearly confirm the effectiveness of fact-checking, we provide policy recommendations to further strengthen its impact.