This is exactly what the study does not find. Indeed, it pretty much confirms what has come to be my view of the evidence on the impact of insurance: you see a very clear impact on utilization, including a handful of recommended preventative screenings, as well as hospitalizations and other treatments. You see a moderately strong effect on both patient and provider finances: fewer medical bills sent to collections, and lower self-reported financial strain from medical costs. And people like being insured, so various self-reported measures rise. The rest is more ambiguous.

For example, the strongest impact on health that they find is that self-reported health status rises by a modest-but-still-significant 0.2 standard deviations: reported depression goes down, while the people who won the lottery were more likely to say that they were in good, very good, or excellent health. This rules out the theory that people who have more contact with the health system might feel less healthy because their doctor gives them more things to be paranoid about, but as Finkelstein et. al note, it doesn’t quite show that they’re actually healthier. Indeed, about 2/3 of the improvement in self-reported physical health comes almost immediately, before people had a chance to consume much in the way of health services; this suggests that the effect may be psychological rather than the result of any improvement in their physical well being. As the authors say “Overall, the evidence suggests that people feel better off due to insurance, but with the current data it is difficult to determine the fundamental drivers of this improvement.”