Polarization and Media Bias

This paper presents a model of partisan media trying to persuade a sophisticated and heterogeneous audience. We base our analysis on a Bayesian persuasion framework where receivers have heterogeneous preferences and beliefs. We identify an intensive-versus-extensive-margin trade-off that drives the media's choice of slant: Biasing the news garners more support from the audience who follows the media but reduces the size of the audience. The media's slant and target audience are qualitatively different in polarized and unimodal (or non-polarized) societies. When the media's agenda becomes more popular, the media become more biased. When society becomes more polarized, the media become less biased. Thus, polarization may have an unexpected consequence: It may compel partisan media to be less biased and more informative