This is one of those policy points liberals are too often scared to make, though it's central to many contemporary policy disagreements. Humans are not rational economic actors. Or, if they are, rationality is hard to pin down, and is certainly no substitute for "prudence." Take the recent accounting of FEMA's post-Katrina aid efforts (please!). The much-vaunted $2,000 debit cards handed out to victims were often swiped in locales a bit removed from grocery stores and low-cost lodgings. According to a recently-released audit, among the purchases were a $450 tattoo, $375-a-day beachfront condos (you'd think hurricane refugees would've wanted some distance from waterfronts), an engagement ring, purchases at "condoms-to-go," and so forth.

I'm not here, though, to criticize spending habits (I'm about to plunk down the better part of a $100 so I can watch all seasons of Coupling whenever I choose). Point is, folks aren't always so careful with their cash. They spend when they should save, they spring for frivolous over sensible, and they exhibit distinct preferences for rapid gratification. True in all cases? Nope. But enough.

Studies also show that fewer than half of all HSA-holders have deposited money in their accounts. Given that the whole concept assumes stockpiling during healthy years to sustain rapid spending during periods of illness, that's trouble. But it's not unexpected trouble. Americans generally have a low savings rate, Americans generally hold an average $8,000 in debt, Americans generally make some bad spending decisions. HSA's assume Americans will act as they generally don't. And while some specific Americans will follow the plan, expect financial chaos when yesteryear's splurges catch up with tomorrow's health problems.

Katrina, in some ways, acts as an excellent test case. The needs were acute, prudent decision-making had to happen then. But it didn't. Stretch the need far into the future and replace free debit cards with hard-earned paychecks, and see if you honestly believe most folks are going to put off the occasional luxury in order to head off the eventual catastrophe. And if so, riddle me this: in a society already possessing bank accounts and tax-advantaged retirement vehicles, why aren't they doing it already?