Advertising restrictions are not the only way in which the agenda laid out in the NAS report would impinge upon the rights of adults. The committee also recommends higher alcohol taxes, suggesting that the levy on beer should be tripled.
It's not clear how effective higher taxes would be at deterring underage drinking. The FTC says "younger minors obtain alcohol primarily through noncommercial means" (e.g., from a neighbor's refrigerator), and the NAS committee notes that "a large percentage of college youth report they do not have to pay anything for alcohol, presumably because they are at a party where someone else is supplying the alcohol." Higher taxes might mean emptier refrigerators or fewer parties, but the ultimate impact on underage drinking probably would be small.
More fundamentally, raising alcohol prices to deter underage drinking is like raising the cost of tickets for R-rated movies to deter 13-year-olds who sneak in without the requisite parent or guardian. In both cases, the appropriate solution is to enforce the age restriction, not to punish responsible adults for the misbehavior of other people's kids.
Another way the policies endorsed in the NAS report affect adults is easily overlooked: When it comes to drinking, current laws put some adults -- 18-to-20-year-olds -- in the same category as children. "Explaining convincingly -- to young people as well as adults -- why alcohol is permissible for 21-year-olds but not for anyone younger is a difficult but essential task," the NAS committee says. "The problem is exacerbated because the age of majority is higher for alcohol than it is for any other right or privilege defined by adulthood."
The report mentions that some people see this situation as not only unfair but counterproductive, since most teenagers are drinking by the time they graduate high school and are ill-prepared to do so responsibly by a policy that treats them like 5-year-olds, demanding abstinence rather than temperance. But that issue, the authors conclude, is beyond the scope of the report requested by Congress. The really interesting questions often are.