The experiment was hugely popular. “For me it is like a gift from the heavens,” one manager told the researchers. Employee wellbeing rose, and workers reported having more time for hobbies, friends and exercise. Another key benefit was improved weekends: Shorter weekly hours meant more errands and chores got done during the week, leaving Saturday and Sunday free for leisure and family activities. And men reported more involvement at home, which reduced women’s stress levels. A gift from the heavens, indeed.

Iceland conducted the trial in part because workers were reporting working more than 40 hours a week — 44.4, to be precise. That makes Icelanders similar to the average full-time worker in the US, who puts in 8.5 hours a day, according to the Bureau of Labor Statistics. According to Gallup, 45 per cent of Americans work nine hours a day or more for a minimum of 45 hours a week.

We shouldn’t be surprised that cutting the length of the workday increased the quality of the work produced in addition to improving employee wellbeing. We lose energy (and effectiveness) as the day wears on. More than a century’s worth of studies back that up. And that’s something companies should remember before they seek a “four-day week” by cramming a 40-hour schedule into four days.

Long work days are taxing, even if they are followed by long weekends. Many people in health care work “four tens,” and many nurses work “three twelves.” While nurses will tell you that the four-day weekends are great, research shows that the long hours are hard. One study found that shifts of 10 hours or more — although often assumed to be necessary for continuity of patient care — are associated with burnout and intent to leave the profession. Mistakes are more likely at the end of a long shift, calling into question whether the practice truly delivers benefits for patients.

Another study in 2021 focused on Japanese consultants found that when people worked overtime they made more errors; shorter days were associated with better results. And a classic study of construction workers in the 1980s conducted by the Business Roundtable found that 60-hour weeks could be maintained for about two months before causing serious delays. Projects would have been completed more quickly, researchers found, had the same crew worked just 40 hours a week.

Yes, there can be benefits to pushing hard in an emergency, like a war. But even there, we run into the limits of the human mind and body. A Stanford study published in 2015 of British munitions workers in World War I found that worker output at 70 hours wasn’t much different from worker output at 56 hours.

The four-day week is a worthy management experiment. But to truly make it successful, companies have to shrink the workweek, not shift it.

There is also a long-term health cost to long hours. Studies of people who work more than 50 hours a week have found that overworkers have higher rates of heart disease, diabetes, depression and alcohol use. While I haven’t yet seen a study that disentangles long days from long weeks, you generally don’t get the latter without the former.

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The four-day week is a worthy management experiment. But to truly make it successful, companies have to shrink the workweek, not shift it.

Bloomberg

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