There’s a fascinating study on newspaper bias by University of Chicago professors Matthew Gentzkow and Jesse Shapiro which identifies the political bias of particular newspapers based on the frequency with which certain phrases appear.
The professors then correlate that placement with the political leanings of the newspaper’s own markets, and find
“That the most important variable is the political orientation of people living within the paper’s market. For example, the higher the vote share received by Bush in 2004 in the newspaper’s market (horizontal axis below), the higher the Gentzkow-Shapiro measure of conservative slant (vertical axis).”
Interestingly, ownership is found to be statistically insignificant once those other factors are accounted for.
James Hamilton, blogging about the study, asks:
“How slant gets implemented at the ground level by individual reporters. My guess is that most reporters know that they are introducing some slant in the way they’ve chosen to frame and report a story, but are unaware of the full extent to which they do so because they are underestimating the degree to which the other sources from which they get their information and beliefs have all been doing a similar filtering. The result is social networks that don’t recognize that they have developed a groupthink that is not centered on the truth.” [my emphasis]
In other words, the ‘echo chamber’ argument (academics would call it a discourse) that we’ve heard made so many times about the internet.
It’s nice to be reminded that social networks are not an invention of the web, but rather the other way around.
h/t Azeem Azhar