December 22, 2005

A biased model?…

Regarding the Groseclose-Milyo study that I mentioned on Tuesday, Mark Lieberman has more to say:

Now, the model’s prediction of the probability for a given congressperson to cite a given think tank is the exponential of the congressperson’s utility for that think tank divided by the sum of the exponentials of their utilities for all think tanks. Because of the exponentials, the numbers assigned as valences — and the resulting utilities — will need to be much more tightly clustered if we want to get a reasonable amount of probability mass distributed over less-favored think tanks. But the basic mathematical fact remains the same: think tank ideology, according to this model, only matters to liberals. Or to put it another way, the more liberal the congressperson, the more weight they give to ideology; the more conservative they are, the closer they come to paying attention only to “valence”, i.e. ideology-free quality.

Statistical models are not my thing. I’m waaaaay out of my league here. But it seems to me that Lieberman’s take on the study undercuts my contention that these “guys really try to connect a textual feature with something like intention.”

In any case, my problem with the study springs mostly from matters of scale. The “media” is a big thing. I simply do not think it’s possible to quantify a pervasive political bias without a wider set of data and content analysis protocols that do a proper job of rhetorical analysis.

And, as I have said before: “Is the news media biased toward liberals? Yes. Is the news media biased toward conservatives? Yes. These questions and answers are uninteresting because it is possible to find evidence–anecdotal and otherwise–to “prove” media bias of one stripe or another. Far more interesting and instructive is studying the inherent, or structural, biases of journalism as a professional practice–especially as mediated through television.”



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