Introducing a cap on working hours would reduce unemployment.  One of the most fundamental principles of economics is that of supply and demand. By artificially reducing the supply (of hours) then demand must increase for other labour, ceteris paribus.  The only question once that is realised is what limit should there be on working hours to ensure full employment. (Or employment at maximum practical capacity.) The purpose of the economy is to serve people, and having a large percentage of people excluded when there is an easy and obvious fix is to fail in the economies mission.