Michael Cannon writes:
On subjective measures of health, the likelihood of screening positive for depression fell from 33 percent to 25 percent, and the share reporting their health to be good or better rose from 55 percent to 68 percent. However, two-thirds of the improvement in self-reported health occurred almost immediately after enrollment, before any increases in medical consumption. The authors posit that much of this improvement could reflect “an improved overall sense of well-being” rather than “changes in objective physical health.”
For the pointer I thank Robin Hanson.