This fall, as parents across the country are sending their sons and daughters off to college, over 100 college presidents signed a proposal to lower the drinking age from 21 to 18.

We are dismayed that so many leaders of institutions of higher learning have signed on to such a proposal, when there is so much evidence against it.

Our nation learned some hard lessons during the 1970s, when a handful of states lowered the drinking age to 18.

In the decade that followed, nighttime fatal crashes in the 18-20 age group increased 17 percent.

Then, when the drinking age was raised to 21 nation-wide, traffic fatalities among this age group decreased dramatically.

It's no wonder the 21 Minimum Legal Drinking Age (MLDA) is considered one of the most effective public health policy initiatives in the history of the United States. Other nations have experienced similar lessons. In 1999, when New Zealand lowered the drinking age from 20 to 18, fatal crashes soared. New Zealand is now debating raising the minimum drinking age to 21.

It shouldn't come as a surprise that the American public overwhelmingly agrees that the current drinking age is just fine. According to a 2002 poll by the Alcohol Epidemiology Program at the University of Minnesota, 80 percent of Americans believe in protecting the 21 MLDA. This is in agreement with other major public health authorities -- including the American Medical Association, Centers for Disease Control, National Highway Traffic Safety Administration and U.S. Surgeon General.

There is also evidence that the 21 MLDA has helped to reduce high school drinking rates. According to national long-term trend data from Monitoring the Future, 12th graders' alcohol usage rates, and binge drinking in particular, are substantially below where they were at the beginning of the 1980s. The most dramatic improvement occurred during the latter 1980's, soon after the drinking age was raised.

What about college drinking?

According to the National Survey on Drug Use and Health, college students are binge drinking, drinking heavily and driving drunk at significantly higher rates than non-students in their age group. There are clearly some other factors at play here. So, what's going on?

In a 2005 study published by the American Journal of Public Health, researchers found that the strongest determinants of college binge drinking are weak alcohol control policies at the state and campus level (the regulatory environment) and overall rates of binge drinking by older adults (a community's overall drinking practices and culture).

In fact, states that severely restrict the promotion and purchasing of alcohol -- such as by requiring registration of keg sales, restricting happy hours and beer pitcher sales and regulating billboards or other advertising -- were found to have half the rate of college binge drinking as states without such policies.

The answer, therefore, is not to make our laws more lax, but rather to establish stronger and consistently enforced alcohol-control policies that will promote a healthier environment on our campuses and in our communities.

Now that the conversation has been started, this is an opportunity for college presidents to engage in dialogue with students and the broader community around this complex issue.

The National Institute on Alcohol Abuse and Alcoholism's report, A Call to Action: Changing the Culture of Drinking at U.S. Colleges, recommends a "3 in 1 approach" to impact individual students, the student body, and the greater community. This multi-layered approach includes providing confidential intervention services for students who are caught drinking, removing alcohol from campus-sponsored events, bolstering campus and community law enforcement and restricting the marketing and promotion of alcoholic beverages both on and off campus. Together, these strategies have shown to decrease the role of...