A shorter workweek has long hovered in the realm of utopian workplace reform, a policy dream tethered more to speculative think pieces than to real political will. But in recent years, the four-day week has gained remarkable momentum, not just as a productivity initiative but increasingly as a public health intervention. Across the UK and globally, evidence is mounting that fewer working hours could deliver substantial health benefits while also challenging conventional assumptions about economic output, workforce engagement, and the role of labour in a society under increasing pressure from burnout, automation, and inequality.

In 2022, the UK hosted the world’s largest four-day week trial, coordinated by 4 Day Week Global in collaboration with researchers at Cambridge University, Oxford University, and Boston College. Sixty-one companies across a range of sectors (from banking and marketing to manufacturing and hospitality) signed up to test the “100:80:100” model: 100% of pay for 80% of the time, in exchange for 100% of output. At the end of the six-month trial, the findings were hard to ignore. Employee stress levels dropped significantly, with 39% reporting reduced anxiety, and 71% experiencing less burnout. Absenteeism fell by 65%, while resignations were down by 57%. But perhaps most surprisingly, productivity was maintained or improved in 91% of the participating organisations.

These figures were echoed by the world’s first medical study of the four-day week conducted by the University of Sussex and learning technology firm Thrive. Participants underwent cognitive tests, sleep tracking, blood tests, and mental health screenings. The results showed not only enhanced psychological well-being, with a 21% increase in overall happiness and a 20% reduction in sleep issues, but also measurable physiological benefits, including lowered cortisol levels and improved cardiovascular indicators. Participants reported feeling more in control of their lives, having better relationships, and engaging more meaningfully with hobbies, childcare, and exercise.

This body of evidence suggests a profound recalibration is possible: that time, not money, might be the currency most critical to health. But for all its promise, the four-day week is not without complications. Critics argue that it represents a luxury afforded primarily to white-collar workers in knowledge-based sectors. Industries with fixed output requirements, such as healthcare, hospitality, and logistics, may struggle to implement shorter hours without compromising service delivery or increasing costs. There’s also concern that compressing work into fewer days could intensify workloads and introduce new pressures, especially if productivity metrics become too rigidly enforced. While proponents argue that better-rested employees are more efficient, it’s unclear whether the 100:80:100 model scales equitably across the economy.

From a macroeconomic perspective, reduced working time could also exert pressure on growth. Standard models of economic output are tightly tied to labour input, and policymakers remain wary of reforms that could reduce GDP in the short term, particularly in countries like the UK, where sluggish productivity growth already undermines fiscal resilience. However, this fear may be outdated. Several studies, including those from the OECD and the New Economics Foundation, suggest that gains in productivity per hour, reductions in health-related absenteeism, and higher staff retention can offset lost hours. Moreover, if shorter weeks reduce reliance on overstretched healthcare systems and improve national well-being, the long-term fiscal benefits could be substantial.

In a 2021 analysis, Autonomy, an independent think tank, modelled a nationwide four-day week in the UK public sector and estimated it could save £1.7 billion per year by reducing sick leave alone. Additionally, in countries like Sweden and Denmark, where work-life balance is already deeply ingrained, workforce participation remains high, health outcomes are better, and productivity is comparable or superior to longer-working countries like the US or Japan. But caution is warranted. If poorly implemented, a four-day week risks reinforcing existing inequalities. For low-income workers and those in precarious jobs, reduced hours could mean reduced pay. In the absence of strong labour protections or universal basic income, these groups may be further marginalised. Similarly, gender inequalities could widen if domestic labour expectations shift disproportionately onto women during their additional day off. A successful transition requires strong collective bargaining frameworks, sector-specific adaptations, and national policies that ensure income security during structural change.

There are also political hurdles. In the UK, successive governments have championed productivity yet avoided the political risks of proposing sweeping labour reforms. The four-day week, while popular among workers, faces resistance from business lobbies and scepticism within parts of the Treasury. Yet this may be changing. The Labour Party has flirted with the idea in recent manifestos, and in devolved governments – such as in Wales and Scotland – interest is growing in small-scale public sector pilots. In Europe, Belgium has legislated a right for employees to request a four-day working week, while in Germany, the powerful IG Metall union is negotiating sectoral deals that could pave the way for permanent reductions in working time.

The shift also raises profound philosophical questions. What is the role of work in our lives? Should human flourishing be measured in output per capita or in the quality of time spent with loved ones, the ability to sleep well, or the freedom to live without chronic stress? As automation, artificial intelligence, and climate disruption reshape our economies, some argue that the four-day week is not merely a labour policy but a moral imperative — a necessary step toward decoupling human worth from productivity and creating healthier, more sustainable societies.

The evidence is strong, and the public appetite is growing. In a 2023 YouGov poll, 63% of Britons supported the idea of a four-day week with no loss in pay. Even conservative-leaning publications have begun to publish cautiously optimistic assessments of the model’s potential. But moving from pilot to policy will require bold leadership, structural innovation, and a serious rethinking of what the future of work looks like in a post-pandemic, post-growth world.

The four-day week may not be a panacea. But in an era marked by record levels of burnout, skyrocketing mental health diagnoses, and crumbling health systems under fiscal duress, it is becoming increasingly clear that working less could be one of the most powerful tools we have — not just to improve individual lives, but to reshape public health, productivity, and social cohesion itself. The question, perhaps, is no longer whether we can afford a four-day week. It’s whether we can afford not to have one.