The 4-Day Work Week: Trial Results

The traditional Monday through Friday, 9-to-5 grind is facing its most significant challenge in a century. Following massive global pilot programs, data suggests that the four-day work week is no longer just a theoretical perk for startups. It is a viable business strategy that maintains productivity while drastically improving employee retention.

The 100-80-100 Model Explained

To understand the trial results, it is essential to define what these companies are actually doing. The successful pilots coordinated by the non-profit organization 4 Day Week Global utilize the “100-80-100” model.

This principle is strict and specific:

  • 100% of the pay: Employees do not take a pay cut.
  • 80% of the time: Working hours are reduced, typically from 40 to 32 hours.
  • 100% of the productivity: The business expects the same output as a five-day week.

This distinguishes the movement from a “compressed” schedule, where employees cram 40 hours into four 10-hour days. The goal here is working smarter, not harder or longer.

The UK Trial: A Landmark Case Study

The most significant data comes from the world’s largest trial to date, which took place in the United Kingdom. Researchers from the University of Cambridge and Boston College monitored 61 companies and approximately 2,900 workers from June to December 2022.

The results challenged the assumption that less time equals less work.

Business Metrics

For the companies involved, the fear of lost revenue was unfounded. Across the participating organizations, revenue remained broadly the same during the six-month trial period. More impressively, when compared to a similar period from previous years, revenue actually rose by 35% on average.

Because of this success, 92% of the companies that participated (56 out of 61) decided to continue with the four-day week after the trial ended. Eighteen of those companies immediately made the change permanent.

Retention and Attendance

The snippet provided mentions a significant improvement in retention, and the data supports this heavily. During the UK trial:

  • Staff turnover dropped by 57%.
  • The number of sick days taken fell by 65%.

For businesses, this represents a massive cost saving. Recruitment, onboarding, and covering for absent employees are expensive logistical burdens. By reducing burnout, companies like Atom Bank (which adopted the model early) and participating marketing agencies found they could hold onto talent in a competitive market.

How Productivity Remained Steady

A common question is how employees produced the same output in eight fewer hours. The trials revealed that productivity was maintained through operational efficiency rather than increased pressure.

Companies implemented several specific changes to make the math work:

  • Meeting hygiene: Meetings were shortened, made optional, or replaced with asynchronous communication tools like Slack or email updates.
  • Focus time: “Deep work” periods were protected, allowing employees to complete complex tasks without interruption.
  • Process automation: Teams identified administrative bottlenecks that could be automated or eliminated entirely.

The theory proved that in a standard 40-hour week, significant time is lost to distractions, fatigue, and low-value activities. By trimming the fat, the actual productive hours remained consistent.

Global Context and Legislative Action

While the UK trial grabbed headlines, the movement is global.

North America

In the United States and Canada, smaller trials involving companies like Kickstarter and Bolt have reported similar success. In March 2024, Senator Bernie Sanders introduced the Thirty-Two Hour Workweek Act in the US Senate. This legislation proposes reducing the standard workweek to 32 hours over a four-year period without a loss in pay, signaling that this conversation has reached the highest levels of government.

Europe

Germany launched a six-month pilot program in February 2024 involving 45 companies. Given Germany’s existing reputation for efficiency but recent struggles with labor shortages, this trial is being watched closely to see if reduced hours can attract more workers to the labor market.

Iceland

Iceland was a pioneer in this space. Between 2015 and 2019, the Reykjavik City Council and the national government ran trials that led to shorter hours for 86% of the country’s working population.

Challenges and Considerations

Despite the glowing data, the four-day week is not a universal fix. It presents specific implementation challenges.

Customer-Facing Roles: Industries that require constant coverage, such as healthcare, retail, or emergency services, cannot simply close on Fridays. These organizations must implement complex rostering systems to ensure coverage while still granting staff reduced hours. This often requires hiring more staff, which can increase costs even if retention improves.

Work Intensification: Some employees in the trials reported that their workdays felt more intense. Because “water cooler” chats and downtime were eliminated to maintain productivity, the pace of the workday increased. However, the extra day off generally compensated for this increased intensity, resulting in lower overall burnout scores.

Frequently Asked Questions

Does the four-day work week mean I work 10 hours a day? No. The modern “100-80-100” model advocates for a 32-hour work week, usually consisting of four 8-hour days. Compressed schedules (4x10) are a different concept.

Do employees get a pay cut? In the successful trials mentioned above, employees received 100% of their pay. The philosophy is that employees are paid for output and value, not specifically for the number of hours they sit at a desk.

Which day do companies usually take off? Friday is the most common day off, giving employees a three-day weekend. However, some companies use a staggered model where half the staff takes Monday off and the other half takes Friday off to ensure the business remains open five days a week.

Are big corporations doing this? While most participants in the trials were Small to Medium Enterprises (SMEs), larger entities are testing the waters. Panasonic introduced an optional four-day work week for its employees in Japan, and Microsoft Japan saw a 40% jump in productivity during a short experiment with the model.