Opinion: What health insurance doesn't do

In one of the most famous studies of health insurance, conducted across the 1970s, thousands of participants were divided into five groups, with each receiving a different amount of insurance coverage. The study, run by the RAND Corporation, tracked the medical care each group sought out, and not surprisingly found that people with more comprehensive coverage tended to make use of it, visiting the doctor and checking into the hospital more often than people with less generous insurance. But the study also tracked the health outcomes of each group, and there the results were more surprising: With a few modest exceptions, the level of insurance had no significant effect on the participants' actual wellness.