But whatever the driving force behind them, some force or forces in the healthcare sector lead it to evolve in a manner favorable to higher productivity producers."
The second piece of new evidence comes from a recent Institute of Medicine report which reaffirmed earlier findings that the substantial variation in Medicare costs across the United States could not reliably be linked to variation in quality.
Yet the report also suggested the principal driver of such variation is not hospitals but rather post-acute-care services - such as skilled nursing facilities, rehabilitation facilities, home health services and hospices.
Were it not for this regional variation in post-acute care, the overall Medicare spending variation would be 73 percent less.
Both of these studies were carefully done, but there are still reasons to be cautious about concluding that hospitals are really wondrous examples of productivity.
For example, the Chandra paper examined only one condition, yet hospitals treat a lot more than just heart attacks.
In any case, the significant variation in productivity within each hospital - how much practice norms differ from doctor to doctor - presents a powerful challenge.
I suspect that this internal variation may diminish over the decade ahead, as digital records are more widely used and as payment systems move away from the traditional fee-for-service model.
Until it does, though, it is too soon to conclude that hospitals are actually efficient.
Orszag is chairman of the financial strategy and solutions group at Citigroup and a former director of the Office of Management and Budget in the Obama administration.