[whstl]

20% reduction of work is not working 20% less. It's working 20% less time.

Productivity and time aren't correlated.

[rascul]

They are largely correlated in just about all work that I've done. Is your experience different?

[whstl]

Yes. Heavily.

Even in cases such as manual work it doesn’t have a directly proportional correlation, since people get tired.

[rascul]

Yes people get tired but I don't see that significantly affecting the amount of work done in general, for 8-9 hour work days. Do you?

[whstl]

Yes, definitely. It also heavily affects the quality.