[dotopotoro]

Other factors to consider (at least theoretically possible):

- shorter week is part of compensation; (possibility to atract more or/and better employees).

- more people will start working/get hired;

- productivity is not uniform thoughout a day/week (tiredeness);

My best counterpoint at the same time is that intuitively I think that 1 person doing 5 days is more productive then 5 persons doing one day each, because communication/coordination does have a cost.

(Surely tradeoffs and optimal points vary from role to role; some tasks are easier to parallelise)