Tell Me What to Do!
Somewhere out there someone is doing something stupid, that isn't yet illegal. One approach is to find that person, jail him, make the act illegal, then pat ourselves on the back. Another approach is to refrain from subsidizing stupidity, and let people pay for their mistakes.
In this case, however, we're really talking about letting children pay for the mistakes of their parents. But where does the first approach end? With the numbers of deaths that occur each year among people who ARE buckled-up, one might conclude that it's irresponsible to seat children in cars AT ALL. Given the thousands of deaths that occur each year among people wearing seatbelts, what parents in their right mind would subject their children to the possibility of a high-speed crash?
Doesn't it follow logically that only people old enough to vote are mature enough to risk their lives in a car?
It does unless you decide to weigh risks and benefits. There's a spectrum of lifestyles from Evil Knievel to coma, each being the result of the set of decisions one makes in life. There is an optimum level of safety in all situations in life. That level is different for different people, at different times and places, and is largely unknowable. Allowing government to make and enforce such decisions is akin to declaring man's perpetual adolescence - yet forgetting that government is composed of such men.
Borrowing from Steven Landsburg, I think that REQUIRING parents to place their children in the trunk of their car (or strapped to the front bumper if space is tight) would result in more careful driving. People without children might be required to rent a baby seal.