The Federal Aviation Administration’s recent decision to require separate airplane seats for babies and toddlers may seem like a no-brainer. Certainly that is the impression that Jim Hall, chairman of the National Transportation Safety Board, has tried to create.

"It doesn’t make any sense to me," Hall said at a safety conference timed to coincide with the holiday travel season, "that during take-off, landing, and turbulence, adults are buckled up, baggage and coffee pots are stored, computers are turned off and put away, but the most precious cargo on that aircraft--infants and toddlers--[is] left unrestrained." Who could defend such a policy?

Until recently, the FAA. The NTSB has been speaking out against the current rule, which allows parents to carry children under the age of 2 on their laps, since 1990. Although you wouldn’t know it from Hall’s remarks, the FAA rejected the board’s advice on public safety grounds.

The FAA’s reasoning was pretty straightforward: Requiring families to buy extra tickets for infants and toddlers (even at half price) would lead some of them to drive rather than fly. Since driving is about 30 times as dangerous (measured by fatalities per mile traveled), the net result could be an increase in deaths.

The fatalities caused by even a small shift to driving could easily outweigh the lives saved by requiring child restraints for babies and toddlers who fly. That’s because air travelers under the age of 2 very rarely die in accidents where a restraint might have made a difference. The NTSB cites only half a dozen such cases in the last 12 years.

FAA Administrator Jane Garvey alluded to the tradeoff between airline and highway fatalities when she announced the agency’s proposed rule. "In past efforts to regulate child restraints," she said, "we were concerned that increased costs of air travel might cause some families to have to travel by car....We don’t want an aviation safety rule to have an unintended consequence that puts families at greater risk on the road."

Having said that, Garvey never explained why the FAA had changed its mind. She simply asserted that "requiring child restraint systems in aircraft is the right thing to do."

Apparently, it is "the right thing to do" regardless of whether it actually saves lives. It is "the right thing to do" even if it results in more dead babies.

The FAA is now singing the same mindless tune as the NTSB. "No matter what mode of transport [parents] choose," said Hall, "they all want to ensure that their children are as safe as possible."

Never mind that this is manifestly not the case. After all, no one is stopping parents from buying extra seats for their babies and toddlers. If they want to, they can shell out a few hundred dollars more (plus the cost of the "child restraint system") so their kids can be "as safe as possible."

If safety really is the only issue, however, they should keep their kids at home. Why take the risk of getting on a plane at all?

In real life, of course, safety is not the only issue. Parents of modest means may well find that they have better things to do with their money than further reduce a risk that is already tiny.

Even apart from the likely increase in highway deaths, it is by no means clear that the government should be second-guessing such decisions. With about 50,000 children under the age of 2 flying every day, estimates University of Chicago economist Allen Sanderson, implementing the FAA’s proposed rule would cost something like $3.6 billion a year in additional air fares.

That amounts to roughly $7 billion for each life saved. By contrast, the FAA traditionally has used a value of about $2 million per life saved to assess its regulations.

The child restraint rule does not make sense even from a practical statist’s point of view. If the government insists on commandeering all that money, it could be used in myriad other ways that would save far more lives.

Then why did the FAA decide to reverse its policy? Garvey gave us a clue when she said, "This is a complex public policy issue--one that requires the perspective of the Secretary of Transportation." The administrator’s deference suggests that the FAA’s reversal was a matter not of safety but of politics, a realm where actual results matter less than good intentions.