Expert Commentary

Ideological segregation online and offline

2011 study from the University of Chicago on news consumers and content selection, highlighting the different levels of polarization in various contexts.


Within the last 30 years, how people get their news has been transformed — traditional newspapers have declined, broadcast TV now competes with endless cable channels, and online news sites and blogs have surged in popularity. In the wake of these changes, some scholars have noted a decline in trusted public figures and institutions; others have expressed concern that the Internet could harm democracy by further polarizing the citizenry, enabling people to read only news that confirms their existing beliefs — so-called cyber-balkanization.

A 2011 study published in The Quarterly Journal of Economics, “Ideological Segregation Online and Offline,” assesses the degree to which online news consumers frequent conservative or liberal sites and compares this information “segregation” to that typically demonstrated and experienced in more traditional contexts. The researchers, Jesse Shapiro and Gentzkow at the University of Chicago, employed user observations and statistical data to calculate the “isolation index” — “the average exposure of conservatives minus the average conservative exposure of liberals” — of news consumers. A higher isolation index number means a higher level of information segregation.

Key study findings include:

  • The average isolation index for readers of online news is 7.5. Consumers of broadcast news (1.8), cable television news (3.3), national magazines (4.7) and local newspapers (4.8) are all less segregated, while readers of national newspapers are moresegregated (10.4).
  • Online news readers are less segregated than many real-world communities, including random individuals within the same zip code (9.4), voluntary associations (14.5), workplaces (16.8), neighborhoods (18.7), families (24.3), and networks of friends (30.3).
  • The four most popular news websites, Yahoo! News, AOL News,, and, make up 50% of all unique online visits, and are “relatively centrist.” The number of liberal and conservative visitors to these sites were within 10 points of each other.
  • Websites with the most conservative readership include (99%), (99%) and (89%); sites with the most liberal readership include (83%), (61%) and (43%). Among more traditional publications, Barron’s topped the list of those with conservative readers (43%); The New Yorker (60%) had more liberal readers.
  • Overall, “the typical conservative or liberal site is … far more extreme than the diet of the typical conservative or liberal user.” For example, “if we were to sample readers from conservative sites like, we would find that most of their readers get most of their news from sites that are substantially less conservative.”
  • The average Internet exposure to conservatives and conservative viewpoints is lower than that experienced on average by the general U.S. adult population in the course of community life, as people often live and work in ideologically homogenous contexts.

The authors note:  “Although consumers’ tastes in news are heterogeneous, they are highly correlated — most people prefer stories that are timely, well written, entertaining and do not omit or explicitly misreport important facts.” Given the high fixed costs of producing news, they add that appealing to a wider audience may translate into more profit, more investment and a higher quality product. The study concludes that “ideological segregation of online news consumption is low in absolute terms, higher than the segregation of most offline news consumption, and significantly lower than the segregation of face-to-face interactions with neighbors, co-workers, or family members. We find no evidence that the Internet is becoming more segregated over time.”

Tags: partisanship

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