I think your rant is slightly misplaced. I agree that it's a huge problem that the US employment-related healthcare system prevents a free or fair market in he

I think your rant is slightly misplaced. I agree that it's a huge problem that the US employment-related healthcare system prevents a free or fair market in health insurance. But the specific problem you describe (and other fixed per-employee costs which would persist even without healthcare) can be addressed by externalizing the cost: pay the four-day employees less than pro rata.