Yeah, probably. But I follow the school of thought that wants to adjust the economy for maximum human happiness, not adjust human happiness for maximum economic growth. So to me, a better question would be: “What is optimum number of hours for each person’s happiness?”
There are a lot of white collar injuries; from this site
This is in the UK, but I have no reason to believe that the statistics would be any different in North America; in fact, they’re probably worse. I would suggest that people working 25% longer each day would result in their injuries happening 25% faster or being 25% more serious. That’s the thing about repetitive strains; you do the same motion for hours every day. Doing the same motion for longer every day puts that much more strain on your body.
Ergonomics is certainly part of this discussion, but so is how long people work at the same task.
Look at it this way: spending 12 hours in an ergonomically-unsound environment is much worse than spending 8.
If I have back pain which develops after 7 hours in a chair that’s inadequate for me and I’m working 8 hour days, then at most I’ll be in pain for 1 hour. If I’m working 12 hour days, that’s 4-5 hours for which I’m useless, plus however long it takes me to recover from the chair.
Would it be best if the chair was good for me? Well, yeah. But we’re looking at the “time” variable here, not at “everything which affects productivity and consumption.”
A good source on this topic is The Overworked American: The Unexpected Decline of Leisure, by Juliet Schor.
6 Am to midnight? When did you sleep? When did you see your family?