I don't see why it has to be thought of this way. It's not a bad way to simplify things, but I don't think it's necessarily the only / main econometrics perspec

I don't see why it has to be thought of this way. It's not a bad way to simplify things, but I don't think it's necessarily the only / main econometrics perspective. Why could a 4 day week result in similar / higher GDP? (not saying it WILL, just pointing out how it COULD) + A big chunk of the jobs are white collar / don't require you to physically be somewhere. If you're a security guard (and you're there mostly for deterrence reasons), then your productivity won't likely change much. Say you get a white collar worker that has a burnout, you'll be producing 10% of your potential. If that extra day of rest prevents the burnout you get x10 for that person. In less dramatic fashion, someone more energized and happy can easily increase productivity by 25% (at least in many of the white collar jobs I'm familiar with) + Network / dynamic effects. Some people won't be more productive, but they might spend the extra day off building something new / learning something new. Even if it's just, say 1/20 that do that, that might offset some of the decreased time working