At Cato Unbound, David Cutler, a Harvard public policy professor whose research I used in The Shangri-La Diet, writes:
The most important reason why medical costs increase over time is because we develop new ways of treating patients and provide that care to ever more people.
At least in his essay, Cutler fails to consider an alternative explanation: Medical costs have increased a lot because we have become a lot more sick — more in need of help. Over the last 50 years, obesity has greatly increased. Diabetes has greatly increased. Depression has greatly increased. Depression, including subclinical depression, is now common and has so many bad effects or correlates — less activity, less socializing, less sunlight, poor sleep, less compliance with everything — that its impact on health must be great.