A Theory of Media Bias and Disinformation

60 Pages Posted: 30 Mar 2022 Last revised: 3 Jul 2023

See all articles by Manuel Foerster

Manuel Foerster

Bielefeld University - Center for Mathematical Economics

Date Written: July 3, 2023


The digital revolution has fundamentally transformed the news industry. To capture these developments, we build a model of media bias in which consumers with heterogeneous beliefs can choose between a variety of news outlets, biased outlets may spread disinformation, and consumers in turn can engage in (informal) fact-checking. We first show that with a single biased outlet fabricated news and fact-checking of counter-attitudinal news naturally are part of any equilibrium. In particular, the consumers who fact-check are those who face high interim uncertainty. Second, competition between biased outlets typically induces moderately biased consumers to follow the outlet that is biased against their belief. We also show how competition in many cases reduces disinformation considerably. Similarly, lowering the costs of fact-checking reduces disinformation and generates a Pareto-improvement for consumers. Finally, in presence of a neutral outlet, echo chambers arise endogenously in equilibrium because only partisans with extreme beliefs follow biased outlets.

Keywords: Disinformation, media bias, competition, news consumption, fabrication, echo chambers

JEL Classification: C72, D82, D83, L82

Suggested Citation

Foerster, Manuel, A Theory of Media Bias and Disinformation (July 3, 2023). Available at SSRN: https://ssrn.com/abstract=4008492 or http://dx.doi.org/10.2139/ssrn.4008492

Manuel Foerster (Contact Author)

Bielefeld University - Center for Mathematical Economics ( email )

Postfach 10 01 31
Bielefeld, D-33501

Do you have negative results from your research you’d like to share?

Paper statistics

Abstract Views
PlumX Metrics