...The crux of the matter is what economists call the adverse-selection problem. Uninsured people with pre-existing conditions often face tens or even hundreds of thousands of dollars in out-of-pocket medical costs annually. If insurers charged everyone the same rate, buying coverage would be far more attractive financially for people with chronic illnesses than for healthy people. And as healthy policyholders began dropping out of the insured pool, it would become increasingly composed of sick people, forcing insurers to raise their rates.
But higher rates make insurance even less attractive for healthy people, causing even more of them to drop out. Before long, coverage would become too expensive for almost everyone. ...
In the 1990s, lawmakers in New York State enacted just such a requirement, and the result was exactly as predicted. Rates for individual policies soared, making New Yorkers’ insurance among the most expensive in the nation. ...
