I live in Poland. We are recently being recognized as a developed economy most often. Still, we earn 1/3 in dollar terms per Capita compared to the US or Germany.

I think 4 days week would result in people having two jobs regularly. I wonder if the situation is simalar with basic job workers in more advanced economies.

One interesing point is that people in my IT company were willing to put 5-10% of their income in exchange for work from home. But this is IT.

I think that the right way to go is not to reduce the number of hours but just allow people to work 4 days per week with hourly rate intact. This might be a very welcomed option by many people.

Also - signing up for this in the high inflation time might work well instead of raising compensations. So this is a good time to carry such experiments.