The common sense reasoning is downright simple: if X hours of works are needed per month, and Y people are available to work, give each person X/Y hours of work each month.
I understand that there are generic frictions that prevent this:
- people not being qualified to do some jobs
- people not wanting to do some jobs
And also specific frictions:
- people not wanting to get a lower salary because of lower working hours.
Without being as extreme as in the introductory example: In a given sector, where there is a surplus of qualified people willing to do a specific job, and whose average salary is higher than the minimal salary necessary to live above the poverty threshold: It makes sense to reduce at the same time salaries and working hours, in order to allow more people to get a salary.
However, except from France which has reduced working time from 39 to 35 hours per months, such measures are not widespread, and seem scarcely considered.
Therefore one wonders whether such measures can actually work. If they do, why are they not more widespread? If they don't, what is the issue preventing them from being effective?