Hypothetically, an economy will split into top tier employers (say 10%), and the rest. The top employers, are usually quasi-monopoly or rent-seeking. So these

Hypothetically, an economy will split into top tier employers (say 10%), and the rest. The top employers, are usually quasi-monopoly or rent-seeking. So these employees can in fact be a bit less productive, and can enjoy the 4 day week, and the employer can remain highly profitable. The rest of the economy is a lot more competitive. These employers already offer lower wages. With 4 -day weeks, these employers will basically get 20% less revenue per employee, and have to cut back even further. So now, the inequality between these 2 sectors will simply become even larger. This is obviously a very gross generalization. EDIT: the counter argument is that in an advanced economy, many many more employers are service-oriented and in the 1st group.