Media Bias

Via Steve Antler comes this paper on media bias that has come up with a pretty neat way of testing whether or not the media has a liberal bias or not. This is the first decent quantitative analysis that I have seen on this. Typcially the work revolves around the party affiliation of reporters, who the voted for, and so forth. While such information is better than nothing it does not provide direct evidence of bias in the actual news stories. This paper actually checks stories (note that editorials, letters to the editor, and book reviews are not counted).

The method, as far as I can tell, works like this. First the Congressional record is used to set up a correspondence between members of Congress and their mention of various think tanks. Then they performed a similar process for various newspapers and news television programs. Also recorded are the legislators ADA scores. Using this information they authors estimate an ADA score for various media outlets (and the think tanks) and it turns out there is indeed a liberal media bias.

For example, the Economic Policy Institute is noted for being rather to the Left/Liberal on many issues and recieves an ADA score of 71.68 (using sentences as the measure) and 70.68 (using citations). The Heritage Foundation by contrast scores 6.17 and 13.75 respectively.

So how much of a liberal bias is there? Well the New York Times comes out pretty liberal (using the back-of-the envelope ADA scores) with estimated ADA scores of 64.6 (using sentences) and 71.2 using citations. Fox News by comparison comes in at 26.4 and 34.7 respectively. Using the estimated numbers using a more sophisticated technique gives the New York Times and Fox News ADA scores of 59 and 29 respectively (using sentences). and 67.6 and 35.6 respectively (using citations).

How "liberal" is this? Well when you consider the average of the medians for the House and Senate is an ADA score of 38 it strikes me as fairly biased. Every evening news television program save Fox News is "to the Left" of the average legislator in Congress.