In the wake of the Brexit vote, many in the UK and around the world aren’t just mourning the loss of European unity. They’re mourning the loss of truth.

Facts and expert opinion didn’t seem to matter much for Brexit voters. Despite outcry from economists that the exit vote would inflict lasting damage on the UK economy, 52 percent decided to leave the European Union anyway.

But why did the voters ignore the data? They had their own set of "facts." In the lead-up to the vote, pro-Brexit politicians fanned the flames of misinformation, spewing baldfaced lies with little blowback.

Terms like "post-factual" politics seem like pundit hyperbole. But then... https://t.co/nduduVT90T pic.twitter.com/9B3T9rNp7v — Jay Rosen (@jayrosen_nyu) June 26, 2016

Look no further than UK Independence Party leader Nigel Farage’s about-face on the morning the polling results came in.

A central promise in the UK’s official "Leave" campaign was that exiting the EU would allow the British government to redirect millions of pounds per week to bolster the National Health Service. Farage, who led a separate pro-Brexit campaign, never contested this claim. Then after the votes were tallied on Friday morning, he admitted that the official Leave campaign was full of it and denied ever having endorsed the idea — despite evidence to the contrary.

We’ve all done it, @Nigel_Farage. A mere slip of the bus. pic.twitter.com/F1eJiXB1QV — Peter Serafinowicz (@serafinowicz) June 24, 2016

"We now appear to live in a post-factual democracy," read one particularly viral reaction to the news of Brexit in the Financial Times.

Much the same could be said about politics on this side of the Atlantic. The election campaign in the US has so far been filled with exaggerations, dubious claims, and pants-on-fire lies.

But all this got us wondering: Are we actually living in a post-factual era? Is there any factual basis to this claim? I reached out to political science researchers, professional fact-checkers, and philosophers who think about these matters to get their take.

Is misinformation more common than ever?

First things first: It’s actually surprisingly hard to say whether there’s more misinformation and political lies around than ever before. We have no good long-term data on whether "truthiness" abounds any more now that it did during the Vietnam War, during the 2003 invasion of Iraq, or during the 19th century’s period of "yellow journalism," Dartmouth political science professor Brendan Nyhan pointed out.

And simply talking about a "post-factual democracy" suggests there was a golden era when politics was based on facts. "I don’t think that time ever existed," Nyhan added.

Still, he said: "My hunch is that people have always been misinformed about lots of things — but the way in which they are misinformed has changed."

Indeed, the internet and social media can make misinformation easier to access, more visible, and harder to sort. Here’s how that may be contributing to political misinformation.

1) People have access to a lot of data — and that can be confusing

All the information now at our fingertips can lead us into cognitive traps, said Michael Lynch, a University of Connecticut philosophy professor and author of The Internet of Us: Knowing More and Understanding Less in the Age of Big Data.

"The more information people have at their disposal, even good information, the more overly confident they become with regard to their own knowledge," he said.

The internet made it possible to reach just about any "fact" you might want at any time. But Lynch explained that the mere fact that we have so much data available can make us think we know more than we do, even when not all of it is helpful or truthful information.

"Just having more doesn’t mean you know more. It has to be good and reliable information," Lynch said, "and whether we have more of that is anybody’s guess."

2) We can now be more selective about the information we see — and don’t see

Having a deluge of data at our disposal requires a certain amount of filtering and self-selection. "Our online lives are curated like a show in a museum," Lynch said. "We select the things to hang on a wall, sources to listen to. That means people can experience this sort of sense of the ground moving underneath them — like when liberals woke up and realized Brexit had happened."

For many people, as Exeter University politics professor Jason Reifler pointed out, these self-curated bubbles probably don’t have much of an impact. "Most people go to work, worry about their families, maybe read a paper or watch news on TV," he said.

Where it makes a difference, perhaps, is for the politically engaged, particularly in this time of polarization. As Vox’s Tim Lee reported, researchers at Facebook found liberal-leaning Facebook users are more likely to see liberal articles in their newsfeeds, while those with conservative affiliations see more conservative articles.

"Partisanship and ideology haven’t just become more polarized but also better sorted," Nyhan said. "So Democrats are more likely to be liberal and Republicans more likely to be conservative, and they tend to associate with people like them, which may prevent them from getting exposed to different kinds of information on the margin."

This state of affairs is fueled by the fact that the traditional gatekeepers of public information — big newspaper outlets, nightly news broadcasts — no longer wield as much influence.

"Politicians have responded accordingly," Nyhan said, reaching out to audiences directly through blogs and social media campaigns. This can help fuel our biases, reinforce our beliefs, shut out opposing views — and perhaps make us more gullible.

3) Misinformation is now more visible

One thing that’s increased in recent years: the visibility of misinformation.

"Social media and the internet have surfaced misinformation that was out there before but not quite immediately available," Nyhan said. "There’s [now] a wider set of claims about ‘facts’ that are being made in the public sphere."

For example, it wasn’t exactly easy for the general population of the 1960s to get their hands on John Birch Society newsletters — documents from the extreme right-wing group that was then promoting paranoid conspiracy theories about widespread communist infiltration.

"The misinformation that was widespread in previous eras wasn’t as immediately visible to people who are outside of the groups that held those beliefs," he added.

Now it’s all a Google search away.

On the other hand, the rise of online fact-checking may have also made peoples’ lies more visible, said Bill Adair, the founder of the Pulitzer Prize–winning fact-checking website PolitiFact and journalism professor at Duke University.

According to his count, between 2015 and 2016 there was a 60 percent increase in active fact-checking sites around the world — from 44 sites to 105. So whether or not the volume of lies is increasing, we may see it more.

Fact-checking can slow the spread of misinformation

Reifler and Nyhan have both talked widely of their studies that have found that fact-checking can have a backfire effect and cause people to stick more closely to their previously held views, particularly when it comes to controversial issues.

But they both said that one of the best ways to combat misinformation was … to continue checking it.

"In some cases, fact-checking can backfire, particularly with people who are resistant to the information in the first place," Reifler said. But, he added, "some of our other research shows the public does benefit from fact-checking." In particular, he and Nyhan have found that when politicians are concerned about how fact-checking might negatively effect their reputation if they are caught telling lies, they’re less likely to be inaccurate.

Reifler even thinks that one of the reasons the reasons the Leave campaign in the UK succeeded is because of the dearth of high-profile fact-checkers there. "There really isn’t anything in the UK that matches the impact of what PolitiFact or the Washington Post fact-checkers do in the US," he says.

The outright lies the Leave campaign told leading up to the referendum were also preceded by years of anti-EU rhetoric that went mostly unchecked and uncontested in the British media.

"Fact-checking needs to be there to stop the little lies before they become big lies," Reifler added. "Prevention is better than antidote. So fact-checking to the extent that it can prevent the spread of misinformation — creating incentives for politicians not to lie, disincentives for them to lie, preventing the spread of misinformation — would be the gold standard."

Let’s hope for more fact-checking on the US campaign trail, where, according to the PolitiFact tally, 12 percent of Hilary Clinton’s fact-checked statements have been false or "pants-on-fire" lies, while 61 percent of Trump's fact-checked statements were the same. As Adair said of Trump, "I can confidently say no major US politician has come close to those sorts of low levels."