In most areas of the economy, free-market principles insure that products and services keep improving, and that consumers get better and better deals. But the free market, though it may be the best way of allocating new TVs and cars, falters when it comes to paying for bypass surgery or chemotherapy. The reasons for this were established nearly fifty years ago, by the economist Kenneth Arrow, in a classic article entitled “Uncertainty and the Welfare Economics of Medical Care.” Arrow showed that health care is distinctive in ways that limit the power of the market. Because people don’t have the expertise to evaluate doctors, hospitals, or treatments, it’s hard for them to comparison-shop. Because they can’t pay for major care out of pocket, they must rely on insurance, thereby often losing the final say in what to buy or how much to spend. More fundamentally, markets work only when consumers have the power to say no if the price isn’t right. Yet it’s very hard for people to say no in the case of things like end-of-life care or brain surgery.