Who is responsible for media bias?

Dr Jesse Shapiro has released an interesting paper [pdf] last month that examined ‘media bias’ in a large sample of US newspapers. The abstract reads:

We construct a new index of media slant that measures whether a news outlet’s language is more similar to a congressional Republican or Democrat. We apply the measure to study the market forces that determine political content in the news. We estimate a model of newspaper demand that incorporates slant explicitly, estimate the slant that would be chosen if newspapers independently maximized their own profits, and compare these ideal points with firms’ actual choices. Our analysis confirms an economically significant demand for news slanted toward one’s own political ideology. Firms respond strongly to consumer preferences, which account for roughly 20 percent of the variation in measured slant in our sample. By contrast, the identity of a newspaper’s owner explains far less of the variation in slant, and we find little evidence that media conglomerates homogenize news to minimize fixed costs in the production of content.

Shapiro analysed the speeches of US politicians in order to identify words used predominantly by either Democrats (the Left) or Republicans (the Right). For example, Republicans used ‘death tax’ whereas Democrats preferred ‘estate tax’. He reduced the list to 1,000 terms and then examined the text of several hundred newspapers, drawing in data on the voting habits of people in each newspaper’s circulation.

He found that the bias of a particular newspaper reflected the demographics of the region in which it was competing. Areas with a large Republican vote were dominated by newspapers with a Republican language bias; and Democrat areas likewise saw papers with a Democrat language bias do well. Interestingly, this was the case even when multiple papers were owned by the same publisher: in Republican areas, they sold papers biased to the Right; and in Democrat areas, they produced papers biased to the Left.

Therefore, the content of newspapers was found to be demand-driven. That is, newspaper publishers will slant their material in order to maximise profit in a particular market. The ideology, as far as it exists, of a paper is therefore a product of its readership rather than its owner. It sounds plausible to a certain extent: nobody would publish material that is ideologically self-satisfying but out of touch with the market and, if they did, shareholders would soon voice their disquiet. The extent to which a paper can afford to slant in either direction without losing readers is, of course, an open question: a paper servicing a right wing readership, for example, might be able to adopt an anti-war position if it continued to be slanted to the right on fiscal and social issues.

However, the research does raise an interesting question about the coverage of Islam in some sections of the press. It is common to hear the media blamed for negative attitudes towards Muslims but is their portrayal of Muslims a reflection of the ideological proclivities of the owner (an editorial dictate) or is this simply what readers demand?