John Maynard Keynes famously predicted a ubiquitous 15-hour workweek by the year 2030 — a direct result of technological advances, he claimed. Written in a 1930 essay, the feasibility of his prediction wanes as 2030 looms closer, and the 40-hour workweek remains the norm.  Still, as many continue to question the efficacy of the 40-hour workweek, Sweden has experimented with a 30-hour one (just six hours per day, as opposed to eight). While still quite a ways from Keynes’s 15-hour workweek, the 6-hour workday trial has been shown to increase efficiency and reduce sick days when implemented.

Of course, questions and doubts remain — How reliable are these trials? How is success measured? Could we garner similar positive results in the United States? And — the big one — how expensive is all this? Below, we delve deeper into the 6-hour workday experiment, and its various successes and failures:

The shortcomings of the 40-hour workweek

In 2014, Stanford University published a study demonstrating the “nonlinear” relationship between hours worked and output. John Hicks, another British economist, speculated that “it has never entered the heads of most employers…that hours could be shortened and output maintained,” and the Stanford study essentially confirms this. It concludes that “below an hours threshold, output is proportional to hours,” but “above a threshold, output rises at a decreasing rate as hours increase.”

With businesses continuing to cite lacking productivity as a persistent issue, it’s not far-fetched to conclude that the 8-hour workday doesn’t serve as well as we’d like. Additional studies document other detriments, including the “chronic condition” of feeling overworked, and even an increased likelihood of making mistakes at work.

The 6-hour workday experiment

For over a year, nurses at the Svartedalens retirement home in Gothenburg have worked 6-hour days for an 8-hour salary in a trial funded by the Swedish government. The experiment is tightly controlled, with data from the Svartedalens home being compared to a control group at a similar facility.

Benefits

As of now, the study has shown that the 68 nurses on the 6-hour workday took half as much sick time as those in the control group, and were 2.8 times less likely to take time off in a two-week period.

The nurses were also reported as 20 percent happier than the control group, believed to have more energy at work and in their spare time, and ultimately were able to do 64 percent more activities with the residents of their facility. As reported in Trouw — a Dutch daily newspaper — residents claimed to feel better cared for, and employees reported feeling healthier.

But how accurate is this data? Well, according to researcher Bengt Lorentzon, the data is very reliable this time around — thanks to the ultimate failure of a previous 6-hour workday experiment in Sweden (due to a lack of reliable data). “This trial is very, very clean because it’s just one homogenous group of workers,” says Lorentzon.

Costs

According to Gothenburg politician Daniel Bernmar, who runs the municipality’s elderly care, the 6-hour workday experiment is “absolutely” associated with higher costs. Ultimately, he says, “it’s far too expensive to carry out a general shortening of working hours within a reasonable time frame.”

And, with the 2-year experiment announcing its end just days ago, it looks like Bernmar is right — costs may have outweighed benefits for the Swedish nursing home. Though the experiment garnered some very real benefits, the retirement home had to hire 17 additional employees to accommodate shortened hours — resulting in high costs for Swedish taxpayers. This need for additional staff added about 12 million kroner ($1.3 million USD) in costs, but about half this expense was allegedly offset by the decrease in sick days and time off.

Overall

New Economics Foundation, a London-based, left-leaning think tank, reports that cutting the work week roughly in half could help to address overwork, unemployment, high carbon emissions, low well-being, entrenched inequalities, and the lack of time to simply enjoy life.

While the Swedish experiments confirms some of these claims, we likely won’t be seeing a homogenized 6-hour workday until experiments to come can prove that the benefits of shorter days outweigh the costs to businesses and taxpayers alike .