In January 2019, YouTube began rolling out the system. That’s when Mark Sargent noticed his flat-earth views take a nose dive. Other types of content were getting down-ranked, too, like moon-landing conspiracies or videos perseverating on chemtrails. Over the next few months, Goodrow and Rohe pushed out more than 30 refinements to the system that they say increased its accuracy. By the summer, YouTube was publicly declaring success: It had reduced by 50 percent the watch time of borderline content that came from recommendations. By December it reported a reduction of 70 percent.
The company won’t release its internal data, so it’s impossible to confirm the accuracy of its claims. But there are several outside indications that the system has had an effect. One is that consumers and creators of borderline stuff complain that their favorite material is rarely boosted any more. “Wow has anybody else noticed how hard it is to find ‘Conspiracy Theory’ stuff on YouTube lately? And that you easily find videos ‘debunking’ those instead?” one comment noted in February of this year. “Oh yes, youtubes algorithm is smashing it for them,” another replied.
Then there’s the academic research. Berkeley professor Hany Farid and his team found that the frequency with which YouTube recommended conspiracy videos began to fall significantly in early 2019, precisely when YouTube was beginning its updates. By early 2020, his analysis found, those recommendations had gone down from a 2018 peak by 40 percent. Farid noticed that some channels weren’t merely reduced; they all but vanished from recommendations. Indeed, before YouTube made its switch, he’d found that 10 channels—including that of David Icke, the British writer who argues that reptilians walk among us—comprised 20 percent of all conspiracy recommendations (as Farid defines them); afterward, he found that recommendations for those sites “basically went to zero.”