The point of a 4-day work week isn't to cram the 5th day into 4 days, it's completely removing the 5th day, thus working 8 hours every day for 4 days, as opposed to 10 hours for 5 days.
And if so, what's stopping them next to increase it back to 5 and chase 5 days worth of productivity out of 5 days/week instead of the previous 4 using the same efficiency gains as performance benchmarks of the 4 days/week?
I don't think anyone can truly deep focus 8 hours a day without burning out at some point.
Of course, but if this is a known fact, why are we still working 5 days a week as the norm and not 4?
Clearly inertia is more important to companies and legislators than facts.
Or that probably not all jobs are so leisurely and inefficient, that 5 days of actual productivity can be don in less.
Many? I doubt it. Maybe many very privileged tech/big-corp workers in developed rich western countries, but globally that's not that many.
Your argument is exactly the argument companies use to justify not going 4 days a week. If workers already have it so good that they have free time to slack off one day out of 5 days per week what's to say they also won't slack off for a day at 4 days per week once that becomes the norm?
Don't get me wrong I'd be al for it, but your comment proves many already have it so much better even at 5 days/week.
And obviously people won't dying because they're sleep deprived but because they're lazy.
Management can say anything, it doesn't make it true.
It reminds me of the way that as we improve in our ability to automate laws, we're going to need to do a better job of thinking about what laws are for rather than assuming that simply reifying the current laws exactly into computerized enforcement will do what we expect: https://news.ycombinator.com/item?id=17094010
Just because a butt is in a seat does not mean a butt is doing work. It wasn't true before, it isn't true now, and it won't be true if they try to squeeze another day out at the new efficiency levels. It may be a common delusion but there is no magic path to that level of productivity.
How didn't it work? Probably the devie you're typing this on was made by a person working 5 days/week, or way more if we're talking early iOS /Android devices.
If you're going to roll with "actually people have in fact been productively working 5 days a week after all" than I would advise FirmwareBurner of 6 minutes ago to take the debate up with FirmwareBurner of 1 hour ago. I don't see that I'd add any value in mediating that discussion.
The top post tries to identify the results as reducing the hours of 5 days of work into 4, the response to that was highlighting that the goal wasn't to make up for missing hours but to try and measure the efficacy of needing that fifth day's 'worth' of hours. You then selectively choose how you interprete the topic to be either:
1) questioning why they couldn't use their results of 5 days VS 4 days to effectively say "if you're effective in 4, then why not 5?
then when questioned on how this doesn't make sense in the context of the article, feign confusion on the distinction and ignore the results of the article to flip flop to your other point:
2) questioning the articles results by asking others outside of the study to personally prove to you what the measure of "success" is since you see modern technology built with this framework (phones) as a reason why it shouldn't change
despite this being a nonsequitor that isn't a point anyone has shown interest in discussing. Then when asked why you went from being confused on why they couldn't use the results showing their effectiveness to try and enforce another "effective" day, to then denying the results and saying that it's already effective and to ask others to personally prove to you why it isn't effective (instead of reading the article).
Do you have any answer yet?
In manufacturing industries this type of schedule is quite common. Not all industries are like tech or will follow it.
Companies that won’t do 4 days (32h) per week might do a slightly longer day instead. Maybe 9 hours worked with an hour lunch
Being paid for less hours (32) per week for 4 days is fine too.