This raises the question of what exactly changed in the 1980s. Daeho Kim, a graduate student at Brown University, offers a provocative hypothesis in a new working paper. As Kim explains, a 1983 Medicare reform created the prospective payment system, or PPS, which offered fixed reimbursements for the use of a medical technology. If a physician decides to use bypass surgery as a cardiac treatment, she won’t be paid on the basis of what it cost her to perform the surgery. Instead, she’ll be paid the national average cost. This way, there is a strong incentive to beat the national average cost of performing bypass surgeries, thus lowering, in theory, systemwide costs.

But something quite different seems to have happened. A big part of the story is that providers can choose from a number of different cardiac treatments, some of which are more expensive than others. PPS encouraged them to focus on the treatments where the marginal cost — the cost of providing one more treatment, in this case — fell below the average cost, even if there are more cost-effective treatments available. Kim suggests that PPS may account for one of the most distinctive aspects of the U.S. health system — our extraordinary overreliance on costly treatments. If Kim is right, it is the failure of bureaucratic price-setting, not the failure of market competition, that may have supercharged health inflation in the 1980s and beyond. We could try to create better price-setting mechanisms. Or we could accept that centralized bureaucracies are just not very good at allocating resources.