Take a day off the working week, keep the pay the same, and surely the work falls off a cliff. Less time at the desk has to mean less done, right? That is the intuition almost everyone starts with, and it is perhaps the reason most companies never try.
However, in 2022, sixty-one British companies decided to test the intuition rather than assume it. The result was not what many people might have expected.
I am not an economist, a workplace researcher, or a management consultant, and I am not a clinician either. This is me reading the results of one large pilot, not handing out advice. The findings below come from a self-selected group of companies that volunteered, reporting partly on themselves, so read them as a signal from one trial rather than a settled law about every workplace.
From June to December 2022, the UK ran what organisers called the world’s largest coordinated four-day week trial. The structure ran on a simple formula. The 100-80-100 model means full pay for 80% of the previous hours, in exchange for keeping output at 100%.
61 companies and around 2,900 workers took part, coordinated by 4 Day Week Global with the campaign group and the think tank Autonomy, and studied by researchers at the University of Cambridge and Boston College. The companies were not a tidy cohort of tech firms. They ranged from manufacturing to financial firms, and each designed its own version of the shorter week rather than copying a single template.
That last detail matters. There was no one method being tested. What was being tested was the principle that hours at a desk and work produced are not the same quantity.
So what happened to output?
By the rough measure available, it broadly held.
Company revenue stayed pretty much flat, rising 1.4% on average over the trial. A four-day week is not a revenue machine, and nobody serious is claiming that.
The useful finding is narrower: the cliff some people expected did not appear. Brendan Burchell, who led the Cambridge team, put it plainly: “Before the trial, many questioned whether we would see an increase in productivity to offset the reduction in working time — but this is exactly what we found.” Productivity appeared to hold up well enough that the lost day paid for itself.
Perhaps more interesting are the people stats. 71% of employees reported reduced levels of burnout by the end of the trial, 39% said they were less stressed, and sick days fell by 65%. Staff leaving dropped sharply too, with turnover down 57% against the same period the year before.
That burnout figure is the one that stops me. Years ago, running my own businesses, I spent a long stretch feeling burned out and fairly hopeless. It was never formally diagnosed, but I know the state from the inside, and it is not a survey category to me. It is the feeling of being switched on and unable to produce, hours stacking up with nothing real coming out of them. When seven in ten people report less of that, it is not a soft perk. It is people getting a part of themselves back.
If any of that feels closer to home than it is interesting, it is worth talking to a qualified counsellor or therapist rather than waiting for a policy to fix it.
At the end of the pilot, 56 of the 61 companies chose to continue the four-day week. A year on, a follow-up found at least 54 still running it, with 31 having made it permanent. Boston College’s Juliet Schor described the effects as “real and long lasting,”.
This is the bit, I think, that really makes the case for a four day work week. Surveys can flatter a thing. These firms had run the experiment on their own books, seen the revenue, seen the staff, and then decided the four-day week was worth keeping without anyone watching.
