Michael Cannon has a defense of his op-ed up over at Cato's blog. He focuses mainly on the argument that health insurance isn't the most cost effective way to improve health, which is certainly a supportable point. But that wasn't the portion of his op-ed I primarily objected to. What angered me was the sentence that read, ""[y]ou may think it is self-evident that the uninsured may forgo preventive care or receive a lower quality of care. And yet, in reviewing all the academic literature on the subject, Helen Levy of the University of Michigan's Economic Research Initiative on the Uninsured, and David Meltzer of the University of Chicago, were unable to establish a "causal relationship" between health insurance and better health."
This is why I called the op-ed misleading, rather than a deliberate lie. What Cannon (and Tanner) are doing is exploiting the public's unfamiliarity with the concept of "causality." I'd bet a maxed-out HSA that most readers understood that passage to say that the researchers couldn't establish a relationship between health insurance and health. As I showed in my rebuttal, the study argued quite the opposite. The problem is, health insurance doesn't lend itself to randomized experiments that can demonstrate causality, and so there's no real way to test the assumption. The closest we've come, the RAND experiment, "provide[d] consistent evidence that health insurance improves health." Cannon and Tanner make it sound like the evidence suggests health insurance doesn't improve health. The study says the evidence suggests the opposite, but causality is difficult to discern because no one wants to deprive individuals of health insurance for the sake of experimentation. So their representation of the conclusion wasn't a lie, per se, it was just very, very misleading, and it was misleading in the direction of their argument.
