It’s Thursday at the online education tech company Treehouse in Portland, Oregon. For most companies, this doesn’t mean anything special. But at Treehouse, Thursdays are Fridays: The company has a four-day workweek. Ryan Carson, CEO and a co-founder of Treehouse, says that he and his wife, Gill, decided to work four-day weeks while launching a tech company in 2004. When they began Treehouse in 2006, he decided to keep the tradition.

“I thought, ‘If everyone says you can’t work less, let’s just prove them wrong,’” he said. “Let’s just do it out of spite. Let’s just not work Fridays and see if it’s possible.” Turns out, it is. Carson says he has found a huge correlation between working less and being more efficient.

“When you look at it, it makes sense. If you think, ‘Hey, if I constrain myself enough to get what I need done and I’m not going to meetings all the time and relaxing and wasting time’ … we find, yes, there’s a huge increase in productivity.”

What Carson found jibes with a larger trend. Anna Cootes, head of social policy at the New Economics Foundation in London wrote a report on working fewer hours. “We do know that people who work shorter hours are more productive hour for hour, so that’s good for the economy,” she says. “We know that a workforce on shorter hours with flexible arrangements tends to be happier, more loyal and stable. You tend to have more women in the workforce, and all those things tend to be good for the business bottom line,” she said.

The United States has the well-deserved reputation of being a nation of workaholics. We work more hours than Canadian, British and French workers. And get this: We work a whopping 42 days more than Germans each year. While Americans are among the world’s most productive workers, more hours does not necessarily mean more productivity.