Can lower working hours beat unemployment? 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?
In Germany in crisis times working shorter hours (short-time work, Kurzarbeit) can be used by firms to prevent layoffs. There are legal regulations how labor unions need to be consulted on how this is done. It has been argued that this has helped to overcome the 2008 crisis better than some other countries, e.g.: "What Explains the German Labor Market Miracle in the Great Recession? The Evolution of Inflation Dynamics and the Great Recession", Brookings Papers in Economic Activity, Spring 2011, Michael C. Burda &amp; Jennifer Hunt; "Explaining the German Employment Miracle in the Great Recession – The 
Crucial Role of Temporary Working Time Reductions", Alexander Herzog-Stein, Fabian Lindner, Simon Sturn, June 2013