Prohibition was never completely repealed -- only those that were deemed of mature years by state legislators were extended the right to purchase alcoholic beverages. The states adopted minimum age laws ranging between 18 and 21. Congress got into the act in 1984, establishing a de facto national minimum age of 21 by threatening the states with loss of highway funds if they didn't get in line. They all did.

Recently the Amethyst Initiative has gained prominence in its call for a reopening of debate on the national minimum. Amethyst is funded by the Robertson Foundation and headed by retired Middlebury College President John McCardell Jr. The 100-plus college presidents who have signed on are no doubt tired of dealing with widespread alcohol abuse on campus in a legal environment in which they must give at least lip service to the absolute ban on drinking.

Here are my thoughts: 1. I doubt that Congress will pay much attention to this initiative, at least in the near future. 2. If I'm wrong and some states lowered the minimum age to 18 or 19, there would be an net increase in alcohol-related problems among teens. 3. Nonetheless, denying college-aged youths the right to drink is so out of line with our collective judgment about adult status, and in particular the age at which we confer the rights and responsibilities of adulthood, that I am inclined to support a rollback in the age minimum.

We tried this before. In the early 1970s, when Congress was still respecting the 21st Amendment, most states lowered their minimum drinking age. That was the time when the Baby Boom cohorts were coming of age and 18-year-old men were subject to the Vietnam draft. The 26th Amendment was adopted in 1970, giving 18 year olds the right to vote. Denying young men who were getting shot up in the war the right to drink when they came home seemed perverse to legislators -- especially when those men could vote.

Twenty-nine states lowered their minimum age by 1975. I and a colleague analyzed the effects on highway fatalities, finding that the relevant age group experienced about a 10% increase in states that lowered their age for all beverage types from 21 to 18, compared with states that didn't change their law. Other research documented this and other indications of increased abuse. President Reagan appointed a commission that documented the problems (with some exaggeration) and ultimately sold Congress on establishing a national minimum.

(Note that we analysts could recite all the theoretical reasons why an age-based prohibition could have perverse effects on health and safety. Those arguments have some truth, but were ultimately trumped by the data. The net effect of lowering the minimum age was to increase alcohol abuse.)

Things have changed since the 1970s, and in some ways it seems likely that the costs of lowering the minimum age would be less now than then. In particular, youthful drunk driving has been curbed by zero tolerance laws, tougher DUI enforcement, and a change in culture that supports having a designated driver. While highway safety remains an important consideration, the greatest acute cost of youthful drinking these days is in its effect on the crime rate. In any event, freedom is still not free in this area.

Yet giving 18-20 year olds the right to drink has a lot going for it. After all, 18 year olds currently can vote, serve on juries, and hold most public offices, enlist in the military or work at any job without parental consent, undertake contractual obligations including marriage, and legally purchase lottery tickets, cigarettes, and shotguns. They are held fully accountable for criminal acts and are too old to receive the protection of the statutory rape laws.

It is also true that while the minimum age law does some good, it's widely violated -- in fact, it's hard to think of another law that is so widely scoffed at. The great majority of older teens choose to drink, with whatever effect that may have on their respect for the law generally.

By the way, even though I support the Amethyst Initiative, I do not think we should do away with a minimum drinking age entirely. High-school students tend to be dangerous to themselves and others, and before age 18 are more children than adults. Parents often welcome some help in providing checks on self-destructive adolescent behavior. But at age 18 or 19, despite the fact that youths are not fully mature (physically or mentally) and still prone to all sorts of hazardous behavior, it is time to swallow hard and make the booze legal.

As I said, I don't believe that Congress will repeal the national minimum. There are various partial measures that might have a better chance. For starters, a handful of states allow underage youths to drink with their parents, at least at home, and other states could adopt that more permissive stance. Enclaves like residential colleges and military bases are relatively safe places, and there might be a carve-out for such insulated environments.

(Actually military base commanders, while generally obligated to observe the local minimum age law, can declare a holiday on the minimum drinking age under special circumstances, such as a return of a combat unit.)

If there was room to compromise, I'd introduce Mark Kleiman's idea of a "learners permit" approach to youthful drinking, whereby a "drinking license" would be given to 18 year olds and subject to suspension if they abused it. The zero tolerance laws on the highway could be maintained to age 21 even if the minimum purchase age were reduced.

It will not surprise anyone who has been scanning these posts that I believe that higher alcohol taxes would help curtail youthful abuse, regardless of the minimum age law, and could serve as a freedom-enhancing, low-cost substitute for age-based prohibition. (Years ago Gary Becker endorsed this idea in his Newsweek column.) Ideally I would want youths to face a higher tax than adults because the external costs of their drinking are so much higher on average. But I haven't figured out how to accomplish that!

[Several who have posted comments on my previous blogs have asked me to respond to their queries. I'll provide a general response tomorrow in my final post.]