Kenneth Arrow

Another in a set of interviews with great economists by Conor Clarke at Atlantic Monthly:
Part one: Economics and business cycles
Part two: Health Care
I guess this is one of my favorite quotations from it:

One point was that health is a random event. It's not like buying automobiles. Whether you're sick or not is hard to predict. Some get sick and some don't. That uncertainty makes it an ideal scenario for insurance. Some houses burn and some don't, but you know whose. So you have fire insurance. (And by the way, financial problems have the same characteristics, and I was always interested in the subject -- the uncertainty.)

Later,

But in the case of health care there are three players: the insurance company with the health plan, the physician, and the patient. The physician presumably has a better knowledge of what the patient needs -- at least better than the insurance company does. So the insurance company could never put together a bill. There is also a Physician and patient relationship, but the physician knows more than the patient.

There are information asymmetries in this story. Health insurance is limping along. It's limited in scope, and then you other consequences. Insurance companies have high premiums to protect themselves. The ones who come to the insurance company are sicker and the people have to pay more. You have adverse selection. You have moral hazard. And the doctor does what's on the safe side -- defensive medicine -- without regard to cost. These are fundamental conditions that make health insurance difficult.

In other words, even if a 2 quart bottle of ketchup costing twice the price of a 1 quart bottle shows market efficiency for ketchup, insurance (and financial) markets work much differently. Of course, I've made these points about adverse selection and moral hazard casually myself, too, but getting them from a Nobel (who isn't Krugman) probably adds more weight.

On the policy side, Arrow had a nice result in his 1951 Ph.D. thesis known as the impossibility theorem.