Health care financing <> Health insurance

From Richard Thaler via the NY Times:

Perhaps the most unpopular feature of the health care legislation now in place is a provision that requires nearly everyone to buy insurance. It is known as the mandate, and it is the aspect of the bill that could end up before the Supreme Court. In contrast, nearly everyone seems to approve of the provision ensuring that pre-existing medical conditions won’t prevent you from finding affordable insurance, as well as the rule that prevents insurers from dropping you if you get sick.

Unfortunately, it is hard to have the popular features without some version of the mandate. A health insurance system cannot work unless most healthy people participate.

Actually, there is a really simple way to cover those with pre-existing medical without imposing an insurance mandate.  Use a tax instead.  Either way, the low risk majority is being asked to subsidize the high risk minority.

Why not use insurance where it makes sense in health care finance and use something else where it doesn’t?