It seems somehow terribly a propos that just as the state of Pennsylvania goes after me for underaged drinking, a group of college presidents urges America to lower the drinking age.  Amen.  It's appalling that someone can go get killed in Iraq, but not buy a beer.

But what about drunk driving?  Mark Kleiman, predictibly, has some eminently sensible suggestions:

Setting the minimum legal drinking age at 21 saves lives by reducing drunk driving, and not just among the 18-to-21's; if 18-year-old high school seniors can buy beer at the supermarket, then 16-year-old high school sophomores have access to it. Common sense and evidence agree: drinking and driving by people who are both inexperienced drinkers and inexperienced drivers is really, really dangerous.

Setting the minimum legal drinking age at 21 also encourages disrespect for the law and encourages young adults to acquire and use false identification documents, which is not a social practice we want to encourage just right now. Moreover, that policy insultingly treats people who are adults for all other purposes as if they were still children, and deprives them of lawful access to an activity that forms part of the normal U.S. social scene and which some of them enjoy. And it may (the evidence isn't clear) lead those who are drinking illegally rather than legally to do so irresponsibly rather than responsibly.

Now, given those facts, what do you want to do about it?

How about looking for policies that would offset the bad effects of lowering the drinking age? They aren't hard to find.

To address the specific problem of youthful drinking and driving, we could -- as some states have already -- change the drunk-driving laws so as to forbid drivers under 21 to drive with any detectable level of alcohol. (These are called "ZT" [for "zero tolerance"] laws.) For someone still learning both to drive and to hold his or her liquor, even a little bit under the influence can be too much. Anyway, a bright line (and zero is a very bright line) may be better observed than a rule that enables the proverbial "two beers."

To address the more general problem of excessive drinking by teenagers (not to mention the still more general problem of excessive drinking, period) we could raise alcohol taxes. This summer has provided a useful object lesson in the Law of Demand: when gasoline prices went up, people drove less. Drinking is the same, especially heavy drinking. Price matters.

I'd add that we should strengthen this with something that Mark himself suggested to me a while ago:  driver's licenses for convicted DUIs that tell bartenders not to serve you.  Combined with a zero tolerance policy, this would be a pretty effective deterrant to drunk driving for teens.  Right now, groups of teens drink together, in secret.  But if your friends can drink at a bar, and you can't, you'll find your social life dramatically curtailed.  Teenagers are very sensitive to penalties that separate them from their friends.  I'd lower the drinking age to 16, as in Europe, but require licenses to show that you haven't had a DUI.

This would also be a more effective deterrent than the current tactic of suspending licenses for DUI, incidentally, since what happens right now is that a lot of chronic drunks get on the road without one.  Let them drive to work--but make it damned difficult for people who drink and drive to get their hands on alcohol.