Here's What Happened When Thousands of Workers Tried a Four-Day Workweek in the Biggest Trial Yet A new study shows that workers on a four-day workweek report being happier and more productive.

The largest trial ever conducted of a four-day workweek found that the schedule had a positive and noticeable impact on employee well-being.

The global study was published on Monday in the journal Nature Human Behaviour and led by Boston College researchers Wen Fan and Juliet Schor. The researchers found that four-day workweeks, where employees work 32 hours a week instead of the traditional 40 hours with no reduction in pay, markedly improved employee health. Workers reported feeling happier, healthier, and higher-performing.

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For example, nearly 70% of employees reported less burnout, over 40% said their mental health improved, and 38% experienced better sleep.

"Beyond maintaining productivity, people just feel so much better," Schor told CNBC about the study findings on Thursday. "They feel on top of their work and their life, and they're not stressed out."

The researchers followed 2,896 employees on a four-day workweek for six months, spanning 141 companies in the U.S., U.K., Canada, Australia, Ireland, and New Zealand. A control group of 300 employees on a standard five-day workweek was used to compare.

Two weeks before the four-day workweek began, employees were asked questions like, "How would you rate your mental health?" and then they were asked again after six months on a four-day workweek schedule. The control group was asked the same questions in the same timeframe, but without starting a shorter workweek.

Fan, an associate professor of sociology at Boston College, was initially worried that worker well-being would "worsen" because employees would feel pressure to be more productive on a schedule with a reduced number of days. But the findings showed that worker stress levels fell. After six months, employees working four days a week instead of five reported an improved ability to complete their work and decreased fatigue. The control group, meanwhile, did not report any significant changes.

"The results indicate that income-preserving four-day workweeks are an effective organizational intervention for enhancing workers' well-being," the researchers wrote in the study.

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Companies are opting to stick to the four-day workweek once they try it. The researchers stated that over 90% of the companies in the experiment kept the four-day work week after the six-month trial period.

Schor wrote in The Wall Street Journal last month that on the employer side, organizations that piloted a four-day workweek found it noticeably improved their bottom line, with revenue increasing and resignations decreasing.

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Over 245 global businesses and nonprofit organizations have trialed a four-day workweek over the past three years, reaching 8,700 employees around the world, Schor noted.

One major company that utilizes a four-day workweek is crowdfunding platform Kickstarter, which started its shortened workweek as a pilot program in 2021. Kickstarter CEO Everette Taylor told investor Kevin O'Leary last year that employees are "very productive' within the four-day week structure.

"I love the fact that the people at our company have [other] interests," Taylor said.

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