WHAT DO THE PAPERS SELL? A MODEL OF ADVERTISING AND MEDIA BIAS

We model the market for news as a two-sided market where newspapers sell news to readers who value accuracy and sell space to advertisers who value advert-receptive readers. In this setting, monopolistic newspapers under-report or bias news that sufficiently reduces advertiser profits. Paradoxically, increasing the size of advertising eventually leads competing newspapers to reduce advertiser bias. Nonetheless, advertisers can counter this effect if able to commit to news-sensitive cutoff strategies, potentially inducing as much bias as in the monopoly case. We use these results to explain contrasting historical and recent evidence on commercial bias and influence in the media.