Media owners maximize profit by giving customers what they want

An interesting effort to determine the direction of causality related in Media Slant: A Question of Cause and Effect by Gregory Mankiw. Mankiw reports on research that documents empirically the perceived political bias in various papers. The researchers are able to rule out owner interference as the source of the bias. I have always attributed it to the cultural milieu of the area or the customer base and the consequent influence that has on the reporters themselves.

More specifically, I think the bias shows up not so much in skewed reporting (though that does happen, sometimes egregiously). Rather, the greatest evidence is in what gets reported and what is avoided. The example that comes to mind is the New York Times' disciplined avoidance of reporting on the John Edwards scandals till long after they were well covered elsewhere and correspondingly their effort to smear John McCain with a poorly sourced allegation of the possibility of an affair. It was the selection of what to report and what not to report that did most of the biasing, not so much the actual reporting per se.

As with most human system issues, the identification of flow of causation is difficult. The researchers have an interesting approach which helps nail this one down.

So, if not the owner’s politics, what determines whether a newspaper leans left or right? To answer this question, Mr. Gentzkow and Mr. Shapiro focus on regional papers, ignoring the few with national scope, like The Times. They find that potential customers are crucial.

If a paper serves a liberal community, it is likely to lean left, and if it serves a conservative community, it is likely to lean right. In addition, once its political slant is set, a paper is more likely to be read by households who share its perspective.

Religiosity also plays a role in the story, and it helps Mr. Gentzkow and Mr. Shapiro sort out cause and effect. They find that in regions where a high percentage of the population attends church regularly, there are more conservatives, and newspapers have a conservative slant. They argue that because newspapers probably don’t influence how religious a community is, the best explanation is that causation runs from the community’s politics to the newspaper’s slant, rather than the other way around.

The bottom line is simple: Media owners generally do not try to mold the population to their own brand of politics. Instead, like other business owners, they maximize profit by giving customers what they want.