Measuring the political slant of U.S. newspapers

by Grace

In most cases, a newspaper’s political slant is determined by the market it serves.

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.

Perhaps this conclusion is obvious to most people, but it does run counter to the idea that media owners “try to mold the population to their own brand of politics”.  In fact, most owners run their newspapers like a business, attempting to “maximize profit by giving customers what they want”.

This was the finding of University of Chicago business professors Mathew Gentzkow and Jesse Shapiro, who studied over 400 daily newspapers to learn more about what drives media slant.  This conclusion was based only “on regional papers, ignoring the few with national scope, like The Times”.

The first part of their analysis measured the political slant of each paper in two ways.

1.  Language-based objective measurement:

Mr. Gentzkow and Mr. Shapiro went to the Congressional Record and used a computer algorithm to find phrases that were particularly associated with the rhetoric of politicians of the two major political parties. They found that Democrats were more likely than Republicans to use phrases like “minimum wage,” “oil and gas companies” and “wildlife refuge.” Republicans more often referred to “tax relief,” “private property rights” and “economic growth.” While Democrats were more likely to mention Rosa Parks, Republicans were more likely to mention the Grand Ole Opry.

With specific phrases associated with political stands, the researchers then analyzed newspaper articles from 2005 to determine which papers leaned left and which leaned right. (They looked only at news articles and excluded opinion columns.) That is, they computed an objective, if imperfect, measure of political slant based on the choice of language.

2.  Reader-submitted subjective measurement:

The authors also used reader surveys of the newspapers’ political orientations, collected from media website Mondo Times.

A plot of this data shows how various newspapers align along the spectrum of political orientation.



FIGURE 1.—Language-based and reader-submitted ratings of slant. The slant index (y axis) is shown against the average Mondo Times user rating of newspaper conservativeness (x axis), which ranges from 1 (liberal) to 5 (conservative). Included are all papers rated by at least two users onMondo Times, with at least 25,000 mentions of our 1000 phrases in 2005. The line is predicted slant from an OLS regression of slant on Mondo Times rating. The correlation coefficient is 0.40 (p = 0_0114).

The few checkpoints for newspapers with which I’m familiar lead me to have confidence in the general accuracy of this chart.  A full-size copy of the chart is on page 47 of the research article linked below.

According to a recent survey, 28% of  journalists identify as Democrats, while 7% call themselves Republicans.


N. Gregory Mankiw, “Media Slant: A Question of Cause and Effect”, The New York Times, May 3, 2014.

Matthew Gentzkow and Jesse M. Shapiro, “What Drives Media Slant? Evidence from U.S Daily Newspapers”, Econometrica, Vol. 78, No. 1 (January, 2010), 35–71.

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