In selling the health care overhaul to Congress, the Obama administration cited a once obscure research group at Dartmouth College to claim that it could not only cut billions in wasteful health care spending but make people healthier by doing so. Wasteful spending — perhaps $700 billion a year — “does nothing to improve patient health but subjects you and me to tests and procedures that aren’t necessary and are potentially harmful,” the president’s budget director, Peter Orszag, wrote in a blog post characteristic of the administration’s argument. Mr. Orszag even displayed maps produced by Dartmouth researchers that appeared to...