Your beloved 4-day workweek would exclude half the American workforce

There was just one problem, says elementary-school teacher Kallie Leyba: “Teachers can’t afford to ski.”

Colorado teachers like Leyba say they already work longer than 40 hours to get paperwork done, on top of receiving among the lowest statewide educator pay. Colorado’s shorter workweek hasn’t helped these major issues, says Leyba, who serves as president of the state’s American Federation of Teachers branch.

As the conversation around fewer work hours gets more traction, experts say at least three segments of the workforce — low-wage workers, teachers, and nurses — could be excluded from the benefits that a shorter workweek provides.

Teachers and nurses represent 6 million people; workers earning less than $15 represent 65 million people. Together, that’s nearly half the labor market.

“Very often when we think about life conflict and over work we have a vision of white-collar workers in mind,” says Daniel Schneider, a researcher at the Shift Project at the University of California at Berkeley. “It’s super important we bring in hourly workers into the conversation.”

As a whole, American workers have some of the worst work-life balance worldwide.

Workers in the US notoriously take less vacation and spend more time at work than employees in other developed countries, and the government doesn’t mandate guaranteed time off.

The lack of work-life balance could be contributing to a mental-health crisis. Over half of employees say their job is negatively affecting their mental health.

But burnout looks different for different workers. Research finds people who work irregular hours or the night shift have a 33% greater risk of experiencing depression on average. That’s why blue-collar workers, like construction workers and paramedics, have higher rates of suicide and depression than the general population.

Domestic workers — think house cleaners and nannies — typically work outside the 9-to-5 workday entirely, sometimes working 24/7, as in the case of live-in nannies. They get paid just $11 an hour, on average, meaning a shorter workweek “won’t cut it for them,” says Julie Kashen, senior policy adviser at the National Domestic Workers Alliance.

“It’s hard to even think about [shorter workweeks] without thinking about the need to increase wages and improve working conditions,” Kashen tells Business Insider.

Along with better work-life balance to prevent burnout, shorter workweeks might increase productivity.

Microsoft, for instance, found that reducing the workweek by one day led to a 40% boost in productivity. A buzzy Wall Street Journal article last month highlighted how employees at a German company got the same amount of work done after cutting three hours in a workday.

Yet the reality for low-wage workers is that they are already being worked to optimal productivity. Scheduling algorithms, such as Kronos, use AI to devise worker shifts around when to best meet a store’s demand. Companies increased use in these scheduling algorithms in the past decade, according to Adrian Haro, CEO of The Workers Lab.

The issue, however, with scheduling technology is that it gives little forewarning to hourly workers on what their daily schedules will look like. As many as 60% of hourly workers get less than two weeks’ notice of changes to their schedule, according to the University of California at Berkeley’s Shift Project.

Schneider, a researcher at the Shift Project, says hourly employees want to work more hours outside of just what these algorithms decide for them.

“The problem is, we do see people working a less-than-40-hour week, but they don’t like it. They want more hours because they’re paid hourly and not very much,” Schneider told Business Insider. “For these workers, there’s a clear time-money trade-off.”

For nearly half of workers, solutions for better work-life balance include higher pay, better staffing, and more fixed schedules — not a shorter workweek.

Leyba said that, as with teachers, nurses are often overworked. A recent report as many as half of nurses and doctors suffer from burnout.

Yet the burnout stems not from time on the job but the quality of work.

Many nurse advocates say working with too many patients is the root of the issue, and groups like Nurses Take DC and SEIU121RNhave lobbied for safer nurse-to-patient staffing ratios. So far, only California caps the number of patients a nurse can have at once, despite research that suggests fewer patients lead to higher-quality patient care.

Similarly, the National Union of Teachers found teachers with larger class sizes work the longest hours. Many teachers have gone on strike over the last few years, most recently in Chicago, protesting increasing class sizes and dwindling pay.

In the case of low-wage, hourly workers, a bill to give people better notice of schedules just got reintroduced into Congress by presidential candidate Elizabeth Warren on Tuesday.