Such a policy can only possibly work for workers who are truly interchangeable, who have no ‘local knowledge’, who are not members of projects, who do not carry work over from one day to the next, etc.
If any of you have read “The Mythical Man-Month”, it talks about the folly of believing that you can cut the time of a software project down by increasing the number of programmers. At a certain point, you run into diminishing returns because management becomes harder, communication between team members more difficult, overlap of responsibilities grow, etc. This applies just as much to an effort to double the size of a team but to work each person half as much. To do that, you’d have to give each person a smaller task load, which means you’re just distributing the work across more people. The net result is an explosion of management and a loss of efficiency.
If you’re a bookkeeper who leaves at the end of the day and picks up work again in the morning on the same set of books you left the day before, how you would like to share that with someone else? How much time would be lost trying to figure out what the other person did? How much extra effort would be required to coordinate your activities and make sure you had a smooth transition process?
There are very few jobs any more that are simply self-contained manual labor with no real information transmission requirements. Maybe a minimum wage worker picking lettuce in a field could be dealt with that way. Or an assembly line worker in a factory.
But for most jobs, this just isn’t the case. There’s even transition overhead for cashiers in a 7-11. When the new shift comes in, the old one has to cash out, balance the cash against the register total, fill out a deposit for the cash, etc. The new one has to set up his or her cash box, make sure the amounts are right, make sure the cash machine has been zeroed out, and all the rest. This can easily take 15 minutes per worker in total. Cut hours in half and double the number of workers, and you just added an extra sunk overhead.
More people also means more sick calls, more HR effort, more late arrivals, more legal paperwork.
Also, if businesses are going to be fined a flat amount for not providing health care, then each worker carries at least a $2000 overhead. Doubling the number of workers doubles the overhead.
The result would be an economic mess. You’d wind up with less overall worker productivity and higher fixed costs of labor. The result would be less competitiveness, and ultimately, lower employment overall.
If it made economic sense to do this, companies would already be doing it.