Echo Chamber Dot Com

#Republic: Divided Democracy in the Age of Social Media by Cass R. Sunstein, Princeton, N.J.: Princeton University Press, 2017, 286 pages.

The 2016 presidential election as well as tumultuous, and sometimes violent, demonstrations recently have had many asking: Is society becoming more polarized along political lines? According to one study, parents in 1960 were much more likely to object to their child marrying someone of a different race than from a different political party; in 2010, the opposite was true. Another study found that the political discourse of the two parties in Congress has become more polarized over time. (See "Interview: Jesse Shapiro," Econ Focus, Second Quarter 2017.)

What is to blame for this apparent trend? In #Republic, Cass Sunstein of Harvard Law School points to online media. Today, individuals can find content for any number of niche topics or viewpoints. Not only that, they are able to filter it based on their interests and preferences — some platforms even do so automatically based on users' viewing habits. While this may be a boon for consumers, who are getting what they want, Sunstein contends that it has troubling implications for democracy.

The book's title references Benjamin Franklin's famous statement on the type of government that the delegates to the Constitutional Convention had designed: "A republic, if you can keep it." Keeping it requires a citizenry well-versed in a variety of issues and viewpoints, according to Sunstein. At first glance, the Internet would appear to be a great enabler of such a society, with information on any topic imaginable just a few keystrokes away. But Sunstein argues that the Internet is being used for precisely the opposite purpose: to reinforce pre-existing beliefs and filter out any challenges to them.

Sunstein argues this point largely in philosophical terms, but he also suggests it is a sort of market failure. He notes that information is a public good because what you know can freely be passed on to others, to their benefit. This means information that may not benefit you directly could still benefit others. From society's perspective, to the extent you fail to capture the benefit of the information that aids others, you'll underconsume information — or so Sunstein contends. But it's unclear that this effect is meaningful as a practical matter; one person underconsuming information does not inhibit others from seeking it out to their own benefit. And as Sunstein notes, the Internet does include general interest news sites without pronounced political slants, fostering serendipitous discovery.

It is certainly true that the Internet can be used to filter content, creating "echo chambers" of likeminded individ­uals. The most chilling example of this, which Sunstein sets out, is the way terrorist organizations have used social media to radicalize and recruit members. Sunstein also cites experiments in sociology showing that when people are divided into likeminded groups, moderate members are influenced by those who hold opinions more strongly, becoming more extreme themselves.

But Sunstein fails to make a compelling case that most individuals online are exclusively seeking out echo chambers. In fact, citing a study by Matthew Gentzkow of Stanford University and Jesse Shapiro of Brown University that finds only a small preference among online users for news outlets that match their political persuasions, Sunstein admits that "most people do not consume news in a partisan way."

Core to Sunstein's thesis is his assertion that the Internet has made it easier to avoid exposure to new information and views than in the past. He contrasts modern society with a time when physical public forums like parks and street corners played larger roles, allowing anyone to engage freely with the public. But it is hard to think of the Internet as anything but such a public forum writ large, and avoiding unsought information online does not seem as easy as Sunstein imagines. Many news sites include comment sections at the end of each article and provide links to other (often unrelated) material on the site. And unless one befriends only likeminded individuals on social media, exposure to novel information and opinions is likely to occur more frequently online than on street corners. Indeed, a recent paper by Gentzkow, Shapiro, and Levi Boxell of Stanford University found that political polarization has grown most quickly since 1996 among older groups who are least likely to use social media or read news online.

Sunstein readily acknowledges the many benefits of social media and the Internet more broadly, and his proposed fixes are ultimately fairly mild. He suggests websites with opposing views could agree to link to each other's content, or that social media services could provide users with more content outside of their expressed interests.

But would such measures address the causes of polarization or just its symptoms? Some researchers have pointed out that the divide in voting patterns between rural and urban residents mirrors a similar divide in health and economic outcomes, suggesting there are deeper issues at work than how we communicate with one another. Still, Sunstein's book is a thoughtful study of how media consumption tailored only to individual desires could exacerbate the divides, even if it isn't necessarily driving them.