What’s struck me about the debate is how it highlights our resistance to good economic news. A central plank of the anti-Elmendorf case is the notion that his budget office has underestimated health care costs. Senator Pat Roberts, the Kansas Republican, went so far this year as to call for a hearing on the subject.

In reality, the Congressional Budget Office – like nearly every other group of health care analysts – has overestimated medical costs. We’re in the midst of a historic slowdown in the growth of medical costs, in which a series of loosely affiliated efforts to cut waste seems to be paying off. Total national spending on health care last year grew at the slowest rate since records began in 1960, the Centers for Medicare and Medicaid Services reported last week.

The Affordable Care Act – specifically, those provisions meant to reward quality, like one that tries to cut down on needless hospitalization – plays some role in the slowdown but is not the main cause. It was instead part of a broader effort among doctors, nurses, hospital executives, policy makers and others to reduce waste. Whatever the cause, though, the result is clear: The Congressional Budget Office has modestly reduced its estimate of the law’s cost since it passed.

Beyond the health law, the budget office has repeatedly cut its estimates of overall health care spending. It now expects Medicare to spend about $11,000 per beneficiary in 2016. As recently as 2006, the forecast for 2016 was about $15,000. Multiplied by millions of Medicare recipients, that’s real money.

How, then, are the budget office’s critics claiming otherwise? Mostly through accounting tricks. For starters, they tend to look only at portions of the health law that spend money and ignore those parts that cut spending or raise taxes. It’s akin to saying a family is going bankrupt because it bought a new car – while overlooking that it also canceled a vacation and that Mom received a raise.