Japan's fans react after their country lost to Belgium in a knockout game in the 2018 World Cup in Russia. (Petr David Josek/AP)

Sports make the world a sadder place. Seriously. We’ve got data.

Armed with 3 million responses to a happiness monitoring app, plus the locations and times of several years worth of British soccer matches, University of Sussex economists Peter Dolton and George MacKerron calculated that the happiness that fans feel when their team wins is outweighed – by a factor of two – by the sadness that strikes when their team loses.

Which means, assuming a roughly equal number of fans on both sides, Sunday’s World Cup final between France and Croatia made the world less happy than it was the day before. On net, soccer is a destroyer of happiness.

To prove it, the researchers analyzed data from an app that pinged 32,000 people several times a day (the precise number varied) and asked them how happy they felt on a 100-point scale, as well as who they were with and what they were doing. The responses included location information, which allowed researchers to determine if they were at a stadium, or had been to one.

They adjusted the results to account for basic differences in happiness based on time of day and day of week. Because they measure differences from each person’s typical happiness level, they were also able to account for people who are, as a rule, permanently miserable or elated. They could not, however, adjust for the app’s users, who tended to be younger and more affluent than the country as a whole.

In the hour immediately after their team wins, researchers found a typical fan might feel about 3.9 points happier than usual – about the same boost as from listening to music. That’s more than offset by the 7.8 points of extra sadness that fans will feel in the hour after their team loses, an event that makes respondents feel about twice as sad as they would be after working, studying or waiting in line.

The researchers call the results “quite dramatic” and say they add up over time. Because post-soccer sadness lingers for hours while after-match joy is fleeting, a loss actually ends up robbing fans of about four times the amount of happiness they might have gained from a win. The effects are much greater if a respondent is actually at the stadium.

Dolton said he saw himself in the data. For as long as he’s followed Newcastle United, the team has underperformed.

“In actual fact, I have seen my team losing key matches at Wembley -- the major stadium -- on seven occasions,” he said. “I have probably experienced more pain than nearly any other football fan.”

Dolton was relieved to learn he had company, and others were as emotionally whipsawed by soccer as he was. “It’s really quite reassuring to know that I’m not unusual,” he said.

So why do people insist on following sports?

In part, the researchers say, it’s because they’re not great at predicting their own team’s success. If you’re the type who believes your team is going to win three out of every five games, then it’s perfectly reasonable to keep watching, even if a loss will make you twice as sad as a win.

“Fans systematically over-estimate the probability of their team winning and never revise and learn from experience,” they write. “Many football fans may continue to go to matches – always in hope and expectation that this particular match will go their way.”

They also write there may be other happiness boosts that didn’t register well in the smartphone app, such as the fleeting high of watching your team score (even if they ultimately lose), the joy of being part of a club of like-minded people, or even the suspense and beauty of the game itself.

Dolton said that, until the country’s loss in the penultimate round, England’s run in the World Cup was proof of sports’ salubrious effects.

“That’s quite an effect on the economy,” he said. “The positive high of the national football team doing well was really quite extraordinary.”

The effect goes both ways, however. Dolton pointed to an analysis by two U.S.-based economists of results from six NFL teams that showed a correlation between worse-than-expected losses and incidents of domestic violence in the area.

“These results are really quite important,” Dolton said. “They’re a marker for all sorts of effects. ”