>You’d need to control for… you get the point. Exactly. And most companies and factories in the west have already optimized for all these factors to get maximum output on a 5 day work week. Moving to a 4 day workweek would be an automatic production loss and therefore a loss on economic competitiveness compared top those still on 5.
What you're talking about, companies who can lower working hours without loosing productivity and competitiveness are very few and far between, usually world champions who have a captive market to themselves like Nvidia, ASML, Airbus, high end service jobs, etc, but that's only a microscopic share of the total amount of players on the market. The rest are firing on all cylinders trying to overtake or catch up to those established market players, and if you ever worked at a startup, it usually means longer hours, not fewer.
>This is a BS way to think about an economic model.
What's the better way? If all companies could get the same levels of productivity form 4 days a weeks from 5 why haven't they done that already?