Research

Media Economics

• "Ranking for Engagement: How Social Media Algorithms Fuel Misinformation and Polarization" (with Vicenç Gómez and Francesco Sobbrio), Journal of Public Economics, 255, 105589, 2026.
• "Rewarding Engagement and Personalization in Popularity-Based Rankings Amplifies Extremism and Polarization" (with Jacopo D'Ignazi, Emma Fraxanet, Andreas Kaltenbrunner, Gaël Le Mens, and Vicenç Gómez), Proceedings of the 32nd ACM SIGKDD Conference on Knowledge Discovery and Data Mining V.2 (KDD ’26), August 09–13, 2026.
• "Analyzing News Engagement on Facebook: Tracking Ideological Segregation and News Quality in the Facebook URL Dataset" (with Emma Fraxanet, Andreas Kaltenbrunner and Vicenç Gómez), EPJ Data Science, 14:73, 2025.
• "Opinion Dynamics via Search Engines (and Other Algorithmic Gatekeepers)" (with Francesco Sobbrio) Journal of Public Economics, 187, 104188, 2020.
• "Time Scarcity and the Market for News" (with Larbi Alaoui) Journal of Economic Behavior & Organization, 174, 173-19, 2020.
• "The Few-Get-Richer: A Surprising Consequence of Popularity-Based Rankings?" (with Vicenç Gómez and Gaël Le Mens) WWW'19: The World Wide Web Conference, 2764-2770, 2019.
• "Concentration and Self-Censorship in Commercial Media" (with Martin Meier) Journal of Public Economics, 97, 117-130, 2013.
• "What Do the Papers Sell? A Model of Advertising and Media Bias" (with Matthew Ellman) Economic Journal, 119, 680-704, 2009.

Other:

• "Media Failures and Media Markets" Els Opuscles del CREI, No. 43, January 2017.
• "Biaixos Informatius I Mercats dels Mitjans de Comunicació" Els Opuscles del CREI, No. 43, January 2017.
• "Regulating for an Independent Media: The Problems of Political and Commercial Bias" (with Matthew Ellman) VoxEU, September 2009.
• "On Commercial Media Bias" UPF WP 1133, 2008. [Quote: “Papa, what is the moon supposed to advertise?” Carl Sandburg, THE PEOPLE, YES, 1936]

Game Theory and Bounded Rationality

• "Uncertain Rationality, Depth of Reasoning and Robustness in Games with Incomplete Information" (with Jonathan Weinstein and Peio Zuazo-Garin) Theoretical Economics, 15(1), 89-122, 2020.
• "Bounded Rationality and Correlated Equilibria" (with Peio Zuazo-Garin) International Journal of Game Theory, 46(3), 595-629, 2017.
• "Global Nash Convergence of Foster and Young’s Regret Testing" (with Gábor Lugosi) Games and Economic Behavior, 60, 135-154, 2007.
• "Stochastic Evolution of Rules for Playing Finite Normal Form Games" Theory and Decision, 62, 311-333, 2007.
• "Existence of Sparsely Supported Correlated Equilibria" (with Gábor Lugosi) Economic Theory, 32, 575-578, 2007.
• "On Some Geometry and Equivalence Classes of Normal Form Games" International Journal of Game Theory, 34, 561-581, 2006.
• "On (Un)Knots and Dynamics in Games" (with Stefano Demichelis) Games and Economic Behavior, 41, 46-60, 2002.
• "On the Indices of Zeros of Nash Fields" (with Stefano Demichelis) Journal of Economic Theory, 94, 192-217, 2000.

Other:

• "Approximate Knowledge of Rationality and Correlated Equilibria" (with Peio Zuazo-Garin) UPF WP 1326, 2012 (also Center for the Study of Rationality DP 610, Hebrew University, Jerusalem, 2012)
• "Quotient Spaces of Boundedly Rational Types" (with Davide Cianciaruso) UPF WP 1287, 2011 (revised 2012) (also CEM-EMS DP 1539, Kellogg, Northwestern University)
• "On Boundedly Rational Rules for Playing Normal Form Games" (2006) in: R. Topol and B. Walliser (eds.) Cognitive Economics: New Trends, Contributions to Economic Analysis, Elsevier, 2006.
• "On Nash Equivalence Classes of Generic Normal Form Games" CORE DP 9833, 1998.

Social Inequality and Cooperation

• "Entropy, Directionality Theory and the Evolution of Income Inequality" Journal of Economic Behavior and Organization, 198, 15-43, 2022.

Microeconomics and Economic Theory

• "Ascending Auctions for Multiple Objects: The Case for the Japanese Design" (with Gian Luigi Albano and Stefano Lovo) Economic Theory, 28, 331-355, 2006.
• "Retaliatory Equilibria in a Japanese Ascending Auction for Multiple Objects" (with Gian Luigi Albano and Stefano Lovo) Review of Economic Design, 10, 1-8, 2006.
• "Bertrand-Edgeworth Equilibria in Finite Exchange Economies" Journal of Mathematical Economics, 39, 677-692, 2003.
• "A Comparison of Standard Multi-Unit Auctions with Synergies" (with Gian Luigi Albano and Stefano Lovo) Economics Letters, 71, 55-60, 2001.
• "Some Consequences of the Unknottedness of the Walras Correspondence" (with Stefano Demichelis) Journal of Mathematical Economics, 34, 537-545, 2000.

Other:

• "On Some Collusive and Signaling Equilibria in Ascending Auctions for Multiple Objects" (with Gian Luigi Albano and Stefano Lovo) UCL/ELSE WP 2002.
• "On the Indices of Zeros of Nash Fields: Extensions and Applications" (with Stefano Demichelis) CORE DP 2000/17, 2000.