Ranking for engagement: how social media algorithms fuel misinformation and polarization

Social media are at the center of countless debates on polarization, misinformation, and even the state of democracy in various parts of the world. An essential feature of social media is their recommendation algorithm that determines the ranking of content presented to the users. This paper investi...

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Detalles Bibliográficos
Autores: Germano, Fabrizio, Gomez, Vicenç, Sobbrio, Francesco
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Universitat Pompeu Fabra
Repositorio:Repositorio Digital de la UPF
OAI Identifier:oai:dnet:rdupf_______::032b032ee6462421bbd4afad3dbc7706
Acceso en línea:https://hdl.handle.net/10230/73310
http://dx.doi.org/10.1016/j.jpubeco.2026.105589
Access Level:acceso abierto
Palabra clave:Social media
Recommendation algorithm
Ranking algorithm
Feedback loop
Engagement
Misinformation
Polarization
Popularity ranking
Algorithmic gatekeeper
Descripción
Sumario:Social media are at the center of countless debates on polarization, misinformation, and even the state of democracy in various parts of the world. An essential feature of social media is their recommendation algorithm that determines the ranking of content presented to the users. This paper investigates the dynamic feedback loop between recommendation algorithms and user behavior, and develops a theoretical framework to assess the impact of popularity-based parameters on platform engagement, misinformation, and polarization. The model uncovers a fundamental trade-off: assigning greater weight to online social interactions—such as likes and shares—increases user engagement but also increases misinformation (crowding-out the truth) and polarization. Building on this insight, the analysis considers how a simple “engagement tax” on social interactions can mitigate these negative externalities by altering platform incentives in the design of profit-maximizing algorithms. The framework is extended to include personalized rankings, demonstrating that personalization further amplifies polarization. Finally, empirical evidence from survey data in Italy and the United States indicates that Facebook’s 2018 “Meaningful Social Interactions” update—which increased the emphasis on certain engagement metrics—contributed to increased ideological extremism and affective polarization.