Companies are shortening the 40-hour workweek to increase employee productivity - here's how it's going around the world

In Sweden, a government study selected a group of retirement-home workers to work 30 hours a week while receiving pay for 40 hours. (Most elder-care in the country is funded by municipal taxes and government grants.)

The study ran from February 2015 to December 2016, and the employees later reported that a six-hour day made them happier and less stressed.

Participating employees enjoyed their work more during this time, but the change was expensive: City officials needed to hire more than a dozen people to cover the shifts left vacated by the roughly 70 workers who got more time off.

The payroll grew about 22% during the study. A local politician told The New York Times that lower unemployment costs offset this hike by roughly 10%, but the overall cost nevertheless increased.

According to The Washington Post, the study also concluded that nurses working six hours a day were more active, less sick, and had less neck and back pain than nurses working eight-hour days.

In August 2016, Amazon announced plans for a pilot program in which some part-time employees would work 30 hours per week.

The company said it would allow about a dozen part-time workers to reduce their number of weekly hours to 30 at 75% of their salary, though they retained all of their benefits.

Participating employees' main hours were 10 a.m. to 2 p.m. Monday through Thursday, with additional flex hours included.

Joe Rubin, a human resources expert who co-founded the recruiting site Crowded.com, previously told Business Insider that Amazon's decision to offer employees more flexibility sends the message that the company values employees' lives outside the workplace.

While Amazon did not immediately respond to a request for comment on the pilot program, the company advertised job openings for positions with 30-hour workweeks as recently as last month.

Treehouse, an online learning platform that offers skill-based courses at a low cost, allowed employees to work 32-hour, four-day workweeks since its launch in 2011.

Ryan Carson, Treehouse's CEO, also decided to eliminate management roles in 2013. Employees could choose their own projects and evaluate each other under this system.

But in 2015, Carson decided to enforce a traditional management structure, according to The Oregonian.

"We were naive," the CEO said. "It was hopeful."

Then, in August 2016, Treehouse laid off nearly 20% of its 104 employees and implemented a five-day workweek the following month.

According to The Oregonian, Carson could not reconcile laying off some employees while letting others work 32 hours a week.

Reusser Design switched to a four-day week in 2013.

Instead of working on Fridays, employees schedules went from 6:30 AM to 5 PM, Monday through Thursday. Company president Nate Reusser told Business Insider that some employees begin at 9 a.m. and work for 10 hours a day.

"When we eliminate distractions or tackle their source, we can be just as productive in four days as we can in five days," the company wrote on its blog. "In fact, we find that we’re just a little more productive."

The company rotates employees on Fridays to answer phones and help walk-in visitors, and accommodates client emergencies as well, according to the blog.

In 2008, Utah became the first state to require state employees to work four days a week.

Former Utah Gov. Jon Huntsman's decision to mandate four 10-hour days was meant to increase efficiency, conserve energy, and help retain employees.

But a 2010 legislative audit showed that the state did not save money this way, and the employees went back to working five days a week the following year, CNN reported.

While the four-day workweek did not benefit the state as a whole, the city of Provo functioned on a four-day week for years before the governor's decision. These days, the Provo mayor's office and other departments are open 7 a.m. to 6 p.m. Monday through Thursday.

John Curtis, the city's mayor, said the system led to improvements in workers' morale and seemed to bring in savings as well, according to Deseret News. Curtis added that four-day workweeks could be better suited for local governments than state governments.