I remember the first time someone told me about working four days for full pay. My immediate reaction? “That sounds too good to be true.” But sometimes the most radical ideas turn out to be the most practical ones.

What started as isolated experiments in small companies has evolved into something remarkable: a growing body of evidence showing that working less can actually make us more productive. The journey from Iceland’s pioneering government trials to Microsoft Japan’s corporate breakthrough to the latest peer-reviewed research tells a story that’s reshaping how we think about work itself.

The Iceland Breakthrough: When Governments Lead#

The story really begins in 2015, when Iceland did something unprecedented. Instead of waiting for corporations to experiment, the Reykjavík City Council and national government launched trials involving over 2,500 workers—about 1% of the country’s entire workforce.

This wasn’t some Silicon Valley startup playing with perks. This was real public sector work: preschools, offices, social services, hospitals. The kind of essential work that keeps society running. Workers moved from 40-hour weeks to 35 or 36 hours while maintaining their full salaries.

The results surprised even the researchers. Productivity either stayed the same or improved across the majority of workplaces. But the human impact was even more striking. Workers reported feeling less stressed and at risk of burnout, and said their health and work-life balance had improved. They also reported having more time to spend with their families, do hobbies and complete household chores.

Will Stronge, director of research at Autonomy, called it “the world’s largest ever trial of a shorter working week in the public sector was by all measures an overwhelming success”. The trials were so successful that unions renegotiated working patterns, and now 86% of Iceland’s workforce have either moved to shorter hours for the same pay, or will gain the right to.

Microsoft Japan: Corporate Validation#

While Iceland was proving government sectors could adapt, Microsoft Japan was about to demonstrate that corporate giants could benefit too. In August 2019, they implemented what they called the “Work Life Choice Challenge 2019 Summer.”

The experiment was elegantly simple: workers at Microsoft Japan enjoyed working four days a week, enjoying a three-day weekend—and getting their normal, five-day paycheck. The result shocked even Microsoft: a productivity boost of 40%.

But the company didn’t just change schedules—they changed how work happened. They slashed meeting times from 60 minutes to 30 minutes and capped attendance at five employees. They encouraged collaborative chat channels rather than “wasteful” emails and meetings.

The efficiency gains went beyond productivity. Electricity costs fell by 23%. With employees taking five Fridays off in August, they printed nearly 60% fewer pages. Microsoft Japan said it became more efficient in several areas, demonstrating that environmental benefits come alongside human and productivity gains.

The news prompted excitement among workers across Japan. Comments ranged from “Here’s to hoping my boss reads about this” to “So I guess me feeling like I’m ready to be done for the week by Wednesday is pretty natural.”

Academic Validation: The Nature Study#

Iceland proved it worked for governments. Microsoft proved it worked for corporations. But science demanded more rigorous evidence. That came in July 2025 with the publication of a groundbreaking study in Nature Human Behaviour.

Led by researchers at Boston College, this study tracked nearly 3,000 workers at 141 businesses across six countries—Australia, Canada, Ireland, New Zealand, the UK, and the USA—after they switched to a four-day workweek with no pay reduction. They compared these workers to similar employees at companies that stuck to traditional schedules.

The findings were comprehensive and compelling. Four-day workers experienced:

  • Greater job satisfaction
  • Less burnout
  • Improved mental health
  • Better physical health

None of these improvements were observed in control companies that maintained five-day schedules.

But perhaps most importantly, the study identified why it works. Three key factors mediated the relationship between shorter hours and improved wellbeing:

  • Improved self-reported work ability (a proxy for productivity)
  • Reduced sleep problems
  • Decreased fatigue

As study co-author Wen Fan explained, “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.”

The Productivity Paradox Explained#

The pattern across all these studies reveals something counterintuitive: working less can make you accomplish more. This isn’t magic—it’s psychology and physiology working in harmony.

When you’re constantly exhausted, your brain operates in survival mode. You make more mistakes, take longer to solve problems, and struggle with creative thinking. The traditional five-day week often pushes people into this state of chronic fatigue.

But give people time to recover—really recover—and something remarkable happens. They come back sharper, more focused, more creative. They waste less time in unproductive meetings because they’re more intentional about how they spend their limited work hours.

The Microsoft Japan results perfectly illustrate this. When they capped meetings at 30 minutes, attendance at five people, and encouraged efficient communication, productivity didn’t just maintain—it soared by 40%.

The Future of Work#

What we’re witnessing isn’t just about schedules—it’s about fundamentally rethinking productivity. The traditional model assumes more hours equal more output. The evidence now suggests the opposite: strategic constraint can drive innovation and efficiency.

Juliet Schor, the study’s other lead author, sees broad implications: “This is a rare kind of intervention that can make employees much better off without undermining the viability of the organizations they work for. Our research shows that both the companies and the employees benefit.”

The research suggests this isn’t just viable for tech companies or small startups. Iceland proved it works in essential public services. Microsoft Japan proved it works for large corporations. The Nature study proved it works across industries and countries.

There are still questions to resolve. How will it scale to very large companies? What industries might face unique challenges? How do we measure productivity gains beyond traditional metrics?

But the fundamental question has been answered. Working four days a week isn’t just possible—it may be better for everyone involved.

The next time someone tells you that working less sounds too good to be true, you can point them to a decade of evidence from Iceland to Japan to peer-reviewed journals. Sometimes the most radical ideas are just common sense waiting for proof.