Partly for my own future reference: comparisons between conventional Medicare and Medicare Advantage, and between Medicaid and private insurance.

The go-to source on Medicare Advantage is the official Medpac report (pdf), which currently finds MA plans costing on average 7 percent more than conventional Medicare. This is less than the premium a few years ago; apparently (pdf) because several changes in Medicare policy more or less incidentally put the squeeze on MA plans. So far those plans are still expanding, but time will tell.

Studies by the Urban Institute and more recently by CBPP find that Medicaid is significantly cheaper than private insurance. This is partly because of lower administrative costs; also, Medicaid, more than Medicare, bargains hard, using things like a limited formulary that lets it drive a harder bargain over drug prices.

And there is, of course, the international evidence: every other advanced country has a less privatized health insurance system than we do, and we have much higher costs than anyone else.

So as I have often said, there’s not a shred of evidence supporting the view that voucherizing Medicare would make the system more efficient; on the contrary.