Private insurers make their money by providing less care per dollar. They cannot raise rates arbitrarily (or if they can, it indicates they have no competition

Private insurers make their money by providing less care per dollar. They cannot raise rates arbitrarily (or if they can, it indicates they have no competition and there's no free market at play) and they cannot reduce the cost of care significantly. The best way for an insurance company to make more money is to simply make fewer payouts. i.e. Reduce the cost center. Every dollar a private insurer makes (or invests) is a dollar they didn't spend on care for their clients. If you assume that insurers have, say, a 5 percent margin, the fastest way to cut the cost of care by 5% is to eliminate the profit.