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A large-scale international study suggests that reducing the workweek to four days without cutting pay leads to improvements in employee well-being, including lower burnout and better physical health. The research tracks nearly 3,000 workers and indicates that these benefits are largely driven by better sleep and a stronger sense of work ability. These findings were recently published in Nature Human Behaviour.
The COVID-19 pandemic fundamentally altered how society views employment and labor markets. High rates of stress and burnout, combined with a surge in resignations, prompted employers to seek new ways to retain staff and maintain morale. One specific intervention gaining attention is the four-day workweek. This model differs from a compressed schedule where employees work longer days to make up for a day off. Instead, it involves working fewer hours for the same salary.
Past studies on working hours often relied on observation rather than intervention. It is difficult to determine if long hours cause poor health or if other factors are at play when looking at data at a single point in time. Previous trials were often small or limited to the public sector in Northern Europe. The new research aimed to test the concept in a diverse range of private companies across multiple countries.
“The pandemic created a perfect storm for exposing unsustainable workloads and accelerating interest in alternatives like the four-day workweek. As many companies around the globe began participating in the four-day week trials, we wanted to understand the well-being impacts of reducing the workweek to four days,” said study author Wen Fan, an associate professor of sociology at Boston College.
“Prior studies tend to rely on single case studies rather than large-scale research involving hundreds of companies. Additionally, both Julie and I have long histories studying work and well-being–Julie wrote an influential book The Overworked American, which remains a classic today, and I have conducted extensive research on workplace flexibility and workers’ health and well-being.”
The research team rooted their investigation in the “job demands-resources” model. This theory posits that long working hours deplete an employee’s mental and physical energy. This depletion leads to exhaustion and distress. Conversely, time off acts as a resource that allows workers to recover from the demands of their roles. The authors wanted to see if an organizational reduction in work time could effectively break the cycle of exhaustion.
To test this, the researchers recruited 141 organizations to participate in a six-month trial. These companies were located in the United States, Canada, the United Kingdom, Ireland, Australia, and New Zealand. The participating organizations agreed to a model where employees worked 80 percent of their regular hours for 100 percent of their pay. To make this feasible, companies underwent a preparation period to redesign work processes and eliminate low-value tasks like unnecessary meetings.
The researchers collected data from 2,896 employees. They administered surveys before the trial began and again after six months. They also collected data from employees at 12 control companies that did not implement the four-day week but were interested in the concept. The surveys measured burnout, job satisfaction, mental health, and physical health. The team tracked the actual number of hours worked to see how much time was saved.
The sample was predominantly female, with women making up about 65 percent of the respondents. The majority of participants were white and held college degrees. Most of the companies involved were in the professional services or non-profit sectors. About 80 percent of the participating organizations had at least 10 employees.
Employees in the trial companies reduced their workweek by an average of about five hours. In contrast, work hours remained stable for employees in the control group. Not everyone reduced their hours by the same amount. Some workers managed to cut eight hours or more, while others saw smaller reductions. This variation allowed the researchers to examine how different levels of time reduction affected the outcomes.
The analysis showed that employees in the trial companies experienced improvements in all four well-being categories. Burnout scores dropped, while job satisfaction scores rose. Both mental and physical health ratings improved over the six-month period. These positive changes did not occur in the control group.
“We find that the four-day workweek improves workers’ well-being,” Fan told PsyPost. “This conclusion comes from comparing changes in four well-being indicators between trial companies and control companies. The control companies were those that initially expressed interest in participating but ultimately did not, for various reasons.”
“We found that employees in the trial companies experienced significant reductions in burnout, along with notable improvements in job satisfaction, mental health, and physical health. In contrast, none of these changes were observed among workers in the control companies.”
The researchers found a connection between the amount of time saved and the benefits gained. Employees who reduced their work hours the most reported the largest improvements in well-being. This pattern was particularly strong for burnout and job satisfaction. Even those with smaller reductions in hours saw some benefits compared to the control group.
Physical health showed the smallest improvement among the four outcomes. The authors note that physical health changes often take longer to manifest than psychological changes. Six months may not be enough time to see dramatic shifts in physical conditions. However, the improvement was still statistically significant.
The researchers looked for the reasons behind these improvements. They identified three key factors that explained the link between shorter hours and better health. First, employees reported better sleep quality. Second, they experienced less fatigue. Third, they reported an increase in “work ability,” which is a measure of how productive and capable a person feels in their job.
The finding regarding work ability is notable. It suggests that the reorganization process helped employees feel more effective. Rather than feeling rushed or stressed by having less time, workers felt they were performing better. This supports the idea of “job crafting,” where employees optimize their workflow to meet demands more efficiently.
The researchers also examined whether the changes happened at the individual level or the company level. They found that simply belonging to a company that reduced hours predicted better well-being. This suggests that organizational norms play a role. When a company collectively values rest and recovery, it benefits employees even if their personal hours do not drop drastically.
“The second major finding is about what explains these improvements,” Fan explained. “We examined various work experiences and health behaviors. We found that three factors played particularly significant roles: work ability (a proxy for workers’ self-assessed productivity), sleep problems, and fatigue. In other words, after moving to a four-day workweek, workers saw themselves as more capable, and they experienced fewer sleep problems and lower levels of fatigue, all of which contributed to improved well-being.”
Long-term data was also collected. The researchers team conducted a follow-up survey at the 12-month mark for the trial companies. They found that the benefits were not temporary. The improvements in well-being were sustained a full year after the trial began. This suggests that the positive effects were not simply due to the novelty of the new schedule.
“Surprisingly, we do not find differences across industries, job types, countries, or demographic characteristics such as gender, parental status, race, or education,” Fan said. “The findings are quite stable and robust, indicating that well-being benefits are broadly shared. I believe this gives us reason for cautious optimism about broader generalizability.”
“That said, we should be careful in making sweeping claims–after all, companies that chose to participate in the trial are not a representative sample. They likely had a higher degree of confidence that the four-day week could work for them. So more research is needed to fully evaluate the broader generalizability of the findings, especially for company outcomes.”
The researchers also checked for the “Hawthorne effect.” This is a phenomenon where people improve their behavior simply because they are being observed. The sustained nature of the results over twelve months argues against this. If it were just an effect of observation, the benefits likely would have faded as the novelty wore off.
But there are still some limitations to this research. The study was not a randomized controlled trial where companies were assigned to groups by chance. The participating companies volunteered for the trial. This means they might already be more supportive of employee well-being than the average firm. This self-selection could influence the results.
Additionally, the data relied on self-reports from employees. While the researchers argue that subjective well-being is best measured this way, objective health data was not collected. It is possible that employees might overstate benefits in hopes of keeping the new schedule. However, the consistency of the data across different questions suggests honest reporting.
The sample was also heavily weighted toward professional services and office jobs in English-speaking countries. This limits how much the findings can apply to other industries like manufacturing or retail. It is also less clear how these results would apply in countries with different labor cultures.
“A common misconception around the four-day workweek is how it’s defined,” Fan noted. “The model we study, for example, is not a compressed workweek, but involves genuine reductions in work hours without reductions in pay.”
“Another misconception is that the four-day workweek only benefits workers. While our research shows clear advantages for employees, it’s also a potential win-win solution for employers. Although we don’t report it in this paper, we’ve observed performance improvements at companies–metrics like revenue, resignation rates, and sick days have improved.”
“Of course, we need to be cautious in interpreting these results, as more sophisticated analyses are needed to account for factors like seasonality or secular trends. Still, around 90% of participating companies chose to continue with the 4-day model after the trial, suggesting they were satisfied with the outcomes. We should also consider the potential broader societal benefits–such as reduced commuting and environmental impact.”
Future research could benefit from government-sponsored trials that allow for randomization. Studies involving larger organizations could also provide opportunities to compare different teams within the same company. The authors suggest that objective measures of health and productivity would add weight to these findings.
“The optimal design would be a truly group-randomized trial, randomly assigning companies to treatment and control groups,” Fan told PsyPost. “However, in reality, it’s often difficult to find companies willing to be randomly assigned to different conditions. One possible solution would be government-sponsored trials where businesses receive incentives — such as tax credits — for participating. Another direction for future research is to work with very large companies where within-company randomization is possible, or where a staggered rollout could create a natural experiment.”
The study, “Work time reduction via a four-day week finds improvements in workers’ well-being,” was authored by Wen Fan, Juliet B. Schor, Orla Kelly, and Guolin Gu.
