You might think a paper’s owner would have some influence on the slant of its coverage, but as a rule, who owns a paper ha less effect than we might think upon its political bias. Note what happens when the same person or company owns papers in different markets. Consider the New York Times Company. It owns what Gentzkow and Shapiro find to be the liberal-leaning New York Times, based in New York City, where roughly 70 percent of the population is Democratic. It also owned, at the time of the study, the conservative leaning, by their measure, Spartanburg Herald Journal, in Spartanburg, South Carolina, where roughly 70 percent of the population is Republican. There are exceptions, of course: Rupert Murdoch’s New Corporation owns what just about anyone would find to be the conservative New York Post. But, overall, the findings suggest that the market determines newspapers slants far more than owners do.

The study has a profound impact on how we think about the news media. Many people, particularly Marxists, have viewed American journalism as controlled by rich people or corporations with the goal of influencing the masses, perhaps to push people toward their political views. Gentzkow and Shapiro’s paper suggests, however, that this is not the predominant motivation of owners. The owners of the American press, instead, are primarily giving the masses what they want so that the owners can become even richer.

Oh, and one more question – a big, controversial, and perhaps even more provocative question. Do the American news media, on average, slant left or right? Are the media on average liberal or conservative?

Gentzkow and Shapiro found that newspapers slant left. The average newspaper is more similar, in the words it uses, to a Democratic congressperson than it is to a Republican congressperson.

“Aha!” conservative readers may be ready to scream, “I told you so!” Many conservatives have long suspected newspapers have been biased to try to manipulate the masses to support left-wing viewpoints.

Not so, say the authors. In fact, the liberal bias is well calibrated to what newspaper readers want. Newspaper readership, on average, tilts a bit left. (They have data on that.) And newspapers, on average, tilt a bit left to give their readers the viewpoints they demand.

There is no grand conspiracy. There is just capitalism.