Microsoft conducted an experiment last summer in Japan. The U.S. software company offered its workers five straight three-day weekends in a country where people put in long hours.

Surprisingly, revenue per employee of Microsoft increased by 40% from the previous year. The company also saved money on bills for power and charges for paper copying.

Similar results were produced by a similar experiment at a New Zealand company in 2018. And Stanford University economist John Pencavel’s study on British plant workers with weapons during World War I found that working more decreases hourly production after a certain point.