We often hear about Facebook’s incredible power over election results—it’s something I’ve reported on frequently this year. This week, we got a sense of just how outsize that power may be.
Tuesday, June 7, is the last day for U.K. citizens to register to vote in the referendum on whether the United Kingdom should remain in the European Union. Last Friday, Facebook began encouraging its users to register to vote in that election by displaying a reminder at the top of their News Feeds.
According to the U.K. government, applications to register spiked that day—but only from users applying online, and not from users applying by paper. About 186,000 people filed voter registration forms online on Friday, more than double the number submitted in the days before:
Voter Registration Applications, by Type
And it was relatively young people who were doing most of that applying. Nearly 120,000 people, aged 34 or younger, registered to vote on Friday, according to the U.K. government. That’s more than the number of registrations filed by all other age sectors combined:
Voter Registration Applications Per Day, Segmented by Age
This correlation was first reported by Dan Barker on Twitter. Because gov.uk, the British government’s website, displays the data by local timezone, users in North America will see the spike occurring on June 2.
It’s important to note this correlation is only that—a correlation—and it’s unclear whether Facebook alone caused the burst in registrations. Friday was also the last day for people living in northern Ireland to apply for a postal ballot for the referendum, for instance; it was also the antepenultimate weekday before the deadline. But the bump in young people registering especially reinforces the Facebook hypothesis, as the platform’s users skew young.
And the spurt in registrations from millennials is likely good news for the “Remain” campaign. An April poll found that most young people support staying in the European Union, but that that demographic was also least likely to vote.
Facebook has no stated corporate position on the EU referendum, and both sides of the referendum use it to campaign and organize. More than 30 million Brits are estimated to use the platform; when it reminded users to register last year; more than 15 million people saw the message. In the United States, Facebook has been pushing similar recommendations on primary-registration deadlines this year. And on Voting Day itself, the company has been encouraging people to cast a ballot for years. Researchers estimate that those appeals have sent hundreds of thousands of people to the polls in the United States.