I would support a 30 hour week (with only getting paid 30 hours). The extra time off would allow parents to spend more time with their kids. Most kids are generally in school for 7 hours. If parents need to bring their kids to school and pick them up, then the kids will be waiting for a long time.
And how would you propose the parents pay for college while making only 30 hours worth of pay? Keep in mind the trade offs.
Didn't think of that one. Good point.
If you were to work 1 hour a day, you would be very productive for that one hour. If you were to work 2 hours, then you would be just as productive for 1 hour, but slightly less productive during the second hour. So the first hour, we will say is 10/10 which is 100%. The second hour may be 9/10 which is 90%. When you get to that 8th hour, you may be at 30%. So if a farmer stopped working a quarter of his time, he would get less work done, but the time spent working would be more efficient - less time would be wasted.
Did you read the article I linked at the beginning of this thread? The French had a 35 hour work week - many workers ended up being more stressed than in the 40 hour week because they had to do 40 hours of work in 35. Again, keep in mind the tradeoffs. Humans aren't machines - you can't just tool them to be more efficient all the time. Having to work harder and faster might also make the job be done sloppier as corners are cut more often to meet deadlines.
I agree humans aren't machines. They will become mentally and/or physically fatigued. The longer they work, the more fatigued they become. If lowering the work week to 30 hours then it should be a given that less work will get done. Perhaps it depends on the type of job and the person on how easily the get fatigued and how efficient they are as the day progresses.