Séminaires LEMMA

"Fact-Checking and Misinformation: Evidence from the Market Leader"

Emeric HENRY (Sciences Po) witth Julia Cage, Nathan Gallo, Moritz Hengel, Yuchen Huang

Tuesday, 2 December 2025, 11h-12h

Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Emeric is Professor at the Economics Department in Sciences Po and chair of the department. He is a microeconomist using theory, experimental and empirical methods to study questions in law and economics, innovation and digital economics.

Abstract : 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.

"Consumers' Privacy Sensitivity in Digital Markets: Evidence from the Mobile App Industry"

Hugo ALLOUARD (ESSEC Business School)

Tuesday, 25 November 2025, 11h-12h

Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Hugo is post-doctoral researcher in economics at ESSEC Business School. His research focuses on industrial organization, digital, public, and labor economics, as well as structural econometrics.