Does having a bias actually sell newspapers?

"I was aware of many newspaper closures since the advent of internet, as many readers started reading their news online," says Agirdas. "I thought that media bias should not change if the bias was driven by the political preferences of the owners/editors of these newspapers. However, if media bias is driven by readers' preferences, a newspaper closure would change the reader base in that metropolitan area, since the surviving newspaper would have an opportunity to appeal to readers of the closed newspaper."

Agirdas used a large panel data set of newspaper archives for 99 newspapers over 240 months (1990- 2009). He found that conservative newspapers reported 17.4% more unemployment news when the President is a Democrat rather than a Republican, before the closure of a rival newspaper in the same media market. This effect is 12.8% for liberal newspapers. After the closure, these numbers were 3.5% and 1.1%, respectively. These findings of a media bias after the closing of a rival newspaper, shows support for Agirdas' theory that a media-bias is demand-driven, as surviving newspapers aim to increase their sales by gaining the former readers of a closed newspaper in the same media market.

"This was quite interesting, because many people blame the media outlets for their bias, instead of the appetite for bias among readers," explains Agirdas. "From time to time, there are calls for restriction of free speech or regulation of the media outlets. There are also calls to split up ownership of media outlets, to avoid monopolization of news. But, if the media outlets are simply serving the preferences of their viewers, such a top to bottom approach would not create better outcomes."