Is Social Media to Blame for Political Polarization in America?

America's widespread adoption of social media and the so-called "echo chambers" it generates have become a popular scapegoat for the rise of political polarization in the U.S., with study after study suggesting voters seeing what they want to see online drives some to more extreme leanings.
But a new report from the National Bureau of Economic Research throws that theory into question, as its findings seem to indicate America's trend toward ideological extremism can't be completely explained away by the popularity of outlets like Facebook and Twitter.