People younger than 21 cannot buy or possess alcohol in the United States, yet that age group accounts for 17.5 percent of consumer spending for alcohol nationwide -- and 90 percent of that is consumed through binge drinking. It's no secret that the legal drinking age is one of America's most frequently violated drug laws, but many have still not realized that having such a high minimum age is doing more harm than good.

Last Friday, I appeared on Katie Couric's talk show, Katie, to talk about teen alcohol use and whether the drinking age should be lowered to 18. I told the audience about my experience enforcing alcohol policy as a Resident Assistant in college, which showed me firsthand that our current approach isn't working. Rather than not drink at all, students drank behind closed doors and pre-gamed before heading out to parties or concerts where they knew they couldn't consume alcohol publicly. This makes them much more likely to overdose, and much less likely to get proper medical attention if they do.

Also in the discussion was John McCardell, president emeritus at Middlebury College and founder of Choose Responsibility; Jan Withers, president of MADD; and Monica Vandehei, a student member of MADD. John has been working on this issue for many years, and more than 130 other college presidents have signed his Amethyst Initiative petition to reconsider the drinking age. He pointed out that the current age hasn't reduced binge drinking, and that it's unreasonable to tell some adults -- who are able to join the military, gamble, and get married -- that they're not responsible enough to drink.

The members of MADD opposed lowering the drinking age, declaring that drunk driving fatalities "skyrocketed" after many states lowered their minimum ages during the 1970s and that raising the age has saved 25,000 lives since then. They also said the 21-year drinking age is "one of the most research-based laws we've ever had," going so far as to claim that the results of every study on the topic have been "all the same," in favor of the current age.

However, this simply isn't true. While drunk driving deaths have declined significantly since the National Minimum Drinking Age Act of 1984 became law, this trend actually started in the 1970s. No study has proven a cause-and-effect relationship between the heightened drinking age and reduced drunk driving deaths, and since similar reductions have occurred in Canada and other countries with lower minimum ages, the drop in fatalities is probably more due to things like public awareness and lowering the BAC limit than the drinking age.

Far from being "all the same," the research on this issue has varied widely. For example, a 2009 study by Harvard Professor Jeffrey Miron concluded that "any life-saving effect in those states that first raised the drinking age was only temporary, occurring largely in the first year or two after switching to the minimum legal drinking age of 21." A large majority of studies have found no relation between the drinking age and other alcohol-related harms like suicide, homicide, or vandalism.

Unfortunately, proponents of the current drinking age rarely look at these other harms and focus solely on drunk driving. While driving under the influence is certainly a major problem, more than 3 out of 5 alcohol-related deaths among people under 21 occur off the road. When we frame the drinking age debate as only about drunk driving, we're ignoring the majority of young people whose lives are destroyed by alcohol. That's why Students for Sensible Drug Policy supports ending the national drinking age: When looking at the whole problem, it's clear that by driving youth alcohol use underground, our high drinking age increases the risk of this substance that is already more harmful than many currently illegal drugs.

Lowering the drinking age is a life-saving reform that people who care about drug abuse should continue to push for, even after turning 21 ourselves. Repealing the federal government's 10 percent highway funding cut for states with ages under 21 would allow them to try new approaches to stopping alcohol abuse. While we fight that battle, there are other important reforms, like 911 Good Samaritan laws, that can help reduce alcohol-related deaths among youth.

The fact that the national drinking age has lasted so long is a testament to the staying power of laws, and a lesson to consider when regulating other drugs for the first time. With up to 58 percent of Americans in support and President Obama now saying it's "important for [the legalization of marijuana in Colorado and Washington] to go forward," it's likely many more states will be legalizing marijuana in the near future. When they do, they should avoid alcohol's bad example and set 18, not 21, as the minimum age for purchase and consumption.

And once the federal government finally repeals marijuana prohibition, it would be wise to let states continue setting their own ages, rather than taking a one-size-fits-all, top-down approach -- we've already tried that with alcohol, and it clearly isn't working.