In 1930 the most famous economist alive made two predictions about your life. He got the first one exactly right. He got the second one so wrong that you are probably reading this slightly tired, wondering where your week went.
John Maynard Keynes was writing at the worst possible moment for optimism. The Great Depression had begun. Into that gloom he published a short essay called “Economic Possibilities for our Grandchildren.” Within a hundred years, he wrote, the standard of living in advanced countries would be four to eight times higher. He was right. On the wealth, Keynes was a prophet.
Then he made his second prediction. If we were going to be eight times richer, we would not need to work nearly as much. He pictured his grandchildren working perhaps fifteen hours a week. Three hours a day was “quite enough,” he wrote, “to satisfy the old Adam in most of us.”1
We are almost at his deadline. The average week in the rich world is somewhere between thirty-four and forty hours, not fifteen.
Was Keynes wrong about the machines?
No. He underestimated us, not the technology.
His logic was simple. Machines would let an hour of work produce far more, and once our needs were met we would take the surplus as free time. The first half came true beyond his imagining. Office productivity has risen around eighty-four percent since 1970 alone, almost all of it from computing.2 On the most cited measures we are about twice as productive as Keynes assumed we would need to be to hit his fifteen hours. The engine did not just arrive. It overdelivered.
Where did the time go?
It went into output, not freedom. Average hours fell through the early and middle of the twentieth century, then stalled around the 1970s and stayed stalled. The productivity kept climbing. The hours did not keep falling.
You can watch the swap in a single career. The office worker of 1970 typed memos and walked to the library to check a figure. Their counterpart today does all of that in seconds and is several times more productive. But that worker did not inherit a three-day week. They inherited a fuller inbox and a higher expectation of how much one person should produce. The productivity became work, one quiet ratchet at a time.
Did we get any of the leisure?
We did, and this is the honest wrinkle. We just took it in a lump, at the end. Expected lifetime leisure in Britain rose around fifty-eight percent between 1931 and 2011, but almost all of it came as longer retirement and longer life, not shorter weeks.3 We chose to work hard for forty years and then stop completely, rather than work gently for sixty. That tells you the surplus to fund a lighter week existed all along. We allocated it somewhere else.
Can a shorter week actually work?
For most of the last century the case was theoretical. It is not anymore. The 2022 UK four-day-week pilot ran six months across sixty-one companies and around 2,900 workers on a 100-80-100 model: full pay, eighty percent of hours, output held at one hundred percent.4 Revenue stayed broadly flat, seventy-one percent reported less burnout, and ninety-two percent of the companies kept the four-day week.5 Iceland ran the largest trial in the world from 2015 to 2019, covering over one percent of its workforce including hospitals and preschools; today around eighty-six percent of Icelanders work shorter hours or have won the right to.6 In 2025 a study in Nature Human Behaviour confirmed the wellbeing gains across 141 organisations in six countries.7
The fifteen-hour week did not fail for lack of capacity. It failed for lack of conversion, the deliberate act of turning productivity into time instead of output. Keynes handed us the engine. He could not hand us the decision. A hundred years on, that decision is still yours.
Frequently asked questions
Did Keynes predict a 15-hour workweek?
Yes. In his 1930 essay Economic Possibilities for our Grandchildren, John Maynard Keynes predicted that by around 2030 people in advanced economies would need to work only about fifteen hours a week, because productivity would have risen so far that basic needs were easily met.
Why did the 15-hour workweek never happen?
The productivity gain Keynes predicted arrived in full. We chose to take it as more output, higher incomes, and more consumption rather than as free time. The hours we saved were reabsorbed by expanding workloads and rising expectations.
Can we actually afford a 15-hour week now?
On the most cited measures we are roughly twice as productive as Keynes assumed we would need to be. The barrier is not capacity but conversion. Four-day-week trials show shorter hours can hold output and pay steady while improving wellbeing.
About the author
Tom Goodwin is the author of Don’t Work Harder, a book about taking the time AI gives back as time rather than more work. He is a co-founder of GAMEPLAN and writes on productivity, technology, and the economics of the working week.
Footnotes
Footnotes
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John Maynard Keynes, “Economic Possibilities for our Grandchildren” (1930), in Essays in Persuasion. Keynes wrote that “three-hour shifts or a fifteen-hour week may put off the problem for a great while.” ↩
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“Whatever happened to the 15-hour workweek?”, The Conversation (2017): office productivity is estimated to have risen about 84 percent since 1970, largely from computing. Read as directional and confirm against primary data. ↩
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Nicholas Crafts, “The 15-Hour Week: Keynes’s Prediction Revisited,” Economica 89 (2022): UK lifetime leisure rose about 58 percent between 1931 and 2011, mainly through longer retirement and life expectancy. ↩
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Autonomy and 4 Day Week Global, The Results Are In: The UK’s Four-Day Week Pilot (February 2023): 61 companies, about 2,900 workers, June to December 2022, on the 100-80-100 model. ↩
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Autonomy, The Results Are In (2023): revenue broadly stable, 71 percent reporting reduced burnout, and 56 of 61 companies (92 percent) continuing the four-day week, 18 permanently. ↩
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Autonomy and Alda, Going Public: Iceland’s Journey to a Shorter Working Week (2021): trials from 2015 to 2019 covering more than 2,500 workers, with about 86 percent of the workforce subsequently on shorter hours or entitled to them. ↩
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Wen Fan, Juliet Schor, et al., six-country four-day-week trial, Nature Human Behaviour (2025): about 2,900 workers across 141 organisations, with significant improvements in burnout, mental health, and job satisfaction. ↩