Yglesias sees this as the nefarious effect of a “hack gap” between the Right and the Left. Even taking the study at face value, though, it would be fairer to say this is what the Right can achieve when it sets up parallel institutions to balance out the left-wing bias in the “mainstream” media. You don’t have to be thrilled with everything Fox News airs or the incentives it creates among rising conservative pundits — or even watch cable news at all; I don’t — to understand why it exists, and why something like it was necessary.
In short, the counterfactual the study considers, a world without Fox News, isn’t an unbiased media environment. It’s a world where everyone gets their news from liberals.
A few years back Tim Groseclose estimated that in the absence of media bias, the electorate would shift markedly rightward. His precise estimates have been disputed, naturally, but whatever the total effect, he clearly got the overall direction of the media’s bias correct. So it’s rather rich for liberals to complain that the deck is stacked against them in the press.