Fake news doesn't create echo chambers; rather, some consumers choose to close their minds.

Zhang, Jiding and Moon, Ken and Veeraraghavan, Senthil K., Does Fake News Create Echo Chambers? (June 23, 2022). Available at SSRN: https://ssrn.com/abstract=4144897 or http://dx.doi.org/10.2139/ssrn.4144897

Abstract: Platforms have come under criticism from regulatory agencies, policymakers, and media scholars for the unfettered spread of fake news online. A key concern is that, as fake news becomes prevalent, individuals may fall into online "echo chambers" that predominantly expose them only to fake news. Using a dataset reporting 30,995 individual households’ online activity, we empirically examine the reach of false news content and whether echo chambers exist. We find that the population is widely exposed to online false news. However, echo chambers are minimal, and the most avid readers of false news content regularly expose themselves to mainstream news sources. Using a natural experiment occurring on a major social media platform, we find that being exposed to false news content causes households to increase their exposure to countervailing mainstream news (by 9.1% in the experiment). Hence, a naive intervention that reduces the supply of false news sources on a platform also reduces the overall consumption of news. Based on a structural model of household decisions whether to diversify their online news sources, we prescribe how platforms should moderate false news content. We find that platforms can further reduce the size of echo chambers (by 12-18%) by focusing their content moderation efforts on the households that are most susceptible to consuming predominantly false news, instead of the households most deeply exposed to false news.

H/t Tyler Cowen.