Lower the drinking age to 18, like almost everywhere else in the world, will decrease the rate of alcohol over-consumption and use of fake ID.
Age 18 is considered adulthood, an age that is expected to take responsibilities. Setting drinking age to 21 will not stop people from drinking, as almost everybody with a college life will know. In contrary, many students will acquire fake identification documents which will be a major support for the document forgery "industry".