It's Not Me, It's You
There are two main points in the Times piece. The first has to do with the way in which the study determined how a news outlet is biased. Authors Matthew Gentzkow and Jesse M. Shapiro looked through the 2005 Congressional Record to find the "1,000 most partisan phrases" that year, a determination based on how often a phrase was used by Republicans or Democrats.
Phrases like "death tax," "illegal aliens," and "Terri Schiavo" were found to have been used most often by Republicans, while "minimum wage," "public broadcasting," and "middle class" were used mostly by Democrats. The authors looked at how often newspapers used these phrases to determined which party they were biased toward.
To some extent, this makes sense. One could argue that a newspaper that uses "death tax" over "inheritance tax," for example, is to some extent tipping its hand. (My favorite such tip-off has to do not with words but punctuation – that is, the decision by the Washington Times to put quote marks around the phrase "gay marriage.") At the same time, if a newspaper were to run a story with the headline "Why The Republicans' Handling of the Terri Schiavo Case Proves Their Incompetence," it's probably not the best evidence that the paper is biased toward Republicans.
The second point is that a newspaper's audience – not the beliefs of its reporters – drives the nature of its slant. "A comparison of circulation data (per capita) to the ratio of Republican to Democratic campaign contributions by ZIP code showed that circulation was strongly related to whether the newspaper matched the readers' own ideology," notes the Times piece. "Their measure indicates that The Los Angeles Times, for example, is a liberal paper. Its circulation suffers in Southern California ZIP codes where donations to Republicans are especially high."
To some extent, we're in "duh" country here – a newspaper in a really red area of the country is likely to be red, while one in a really blue area is likely to be blue. Newspapers want to appeal to their potential audience, and to do so they need to reflect it. It's still worth thinking about, however, if only because it means that customers, not reporters or owners, are responsible for media bias. Sorry guys!
It would be ridiculous to take this line of thinking too far, of course. The individuals responsible for the news do matter, and their beliefs matter. But there could still be something to this. In the long run, for example, a correlation could potentially be found between, say, the increasing liberalism or conservatism of newspapers like the New York Times and USA Today and the shifting political beliefs of large numbers of Americans. This way of thinking also puts the whole "civil war" debate in a whole new perspective. The decision to call the situation in Iraq as such wasn't, by this logic, about the biases of NBC, or even the reality on the ground. It was instead simply a reflection of what the electorate wanted to hear.