I've seen no compelling evidence to suggest that working fewer hours will raise efficiency enough to result in the same amount of work being done in those fewer hours. It _can_ be true, but it seems unlikely enough (to my intuition) that I'll assume it would not be the case unless someone can put forth a convincing argument/evidence.
I really support 4x9, though, for a lot of reasons. It should become a work norm (and 36 hours set as the nominal workweek by government).
- I do think productivity will go up some, and the fall in output will be less than 10%. Split the difference, and call it 5%.
- Because there will be some fall in output, and because there are some professions where you need butts-in-seats for coverage... I think it will, by reducing the supply of labor, push up the equilibrium price and get more people into skilled work.
- It's a hedge against automation reducing demand for labor.
- I think we'll recognize a lot of ancillary benefits from reduction of commute times, etc.
