Paradoxically, productivity seems to be enhanced by the shorter working hours. “What we can see today is that employees are at the very least doing the same amount in the six-hour workday, often more than they did in the eight-hour day,” said the manager of a Toyota repair facility.
The idea is that workers who are fresher and less stressed can contribute more in their shorter working day, to the benefit of all.
Sweden has a long history of experimenting with work-life balance. It's one of the things I love about the culture there.