It's interesting that you completely dismiss the hypothesis that they could actually be more productive in the fewer hours which I find quite plausible.
When the 40hr work week came in, it was in part pushed by industrialists because it produced higher productivity than longer hours. That was for relatively low creativity work.
Every investigation that I know of that has looked at this matter finds that working more than 40hrs a week gives you a relatively short boost (2 weeks or so) and within a few more weeks, you're producing less over your 60hrs than you would if you'd just worked 40 the whole time.
It's quite plausible to me that this is true for 32 hours too for particularly creative jobs.
It might actually be an advantage that helps them defeat the cut-throat competition to work a 4 day week.
When the 40hr work week came in, it was in part pushed by industrialists because it produced higher productivity than longer hours. That was for relatively low creativity work.
Every investigation that I know of that has looked at this matter finds that working more than 40hrs a week gives you a relatively short boost (2 weeks or so) and within a few more weeks, you're producing less over your 60hrs than you would if you'd just worked 40 the whole time.
It's quite plausible to me that this is true for 32 hours too for particularly creative jobs.
It might actually be an advantage that helps them defeat the cut-throat competition to work a 4 day week.