At least one Guam news website trumpets the July 2010 law change as a success. For example, they note (correctly) that according to the 2011 Youth Risk Behavior Survey (YRBS), 13.6% of Guam's high school students engaged in "binge" drinking, compared to 19.2% in 2007, the last available year in the survey before the law change. This drop by nearly a third sounds impressive until you consider the following facts:
- The decline in high school "binge" drinking actually began in 2001, from a high of 24.9%. The drop from 2001 to 2007 was almost as large as the drop from 2007 to 2011.
- The figures also declined in the nation as a whole, from 29.9% in 2001 to 26.0% in 2011 to 21.9% in 2011.
- Due to the fact that the surveys were not done every year, we have no idea when the decline in Guam began to accelerate.
- For grades 9 and 10, the differences in "binge" drinking rates between the years 2007 and 2011 were not statstically significant, despite the fact that the differences were significant for the nation as a whole.
- In fact, 9th and 10th graders in Guam actually saw increases in self-reported riding with a drinking driver, while the mainland saw decreases. So much for the trickle-down theory.
- Guam's teen drinking and "binge" drinking rates have been consistently below the national average, even when their drinking age was 18.
- Compared with 2007, high school students in Guam saw increases in boozy sex as well as unprotected sex in 2011.
The most recent Uniform Crime Report for Guam is for 2010. In it we see that total DUI arrests dropped significantly from 2009 but nonetheless remain higher than 2008. DUI arrests for 18-19 year olds were 42 in 2008, 52 in 2009, and 35 in 2010, which was a slight decrease from 2008. (Data for 20 year olds in 2010 was lumped in with 21-24 year olds, so it could not be used.) Juvenile crime (i.e. under 18) saw zero progress overall in 2010, and in fact nearly doubled from 2009. Specific crimes that rose in 2010 among juveniles included not just DUI but also murder, rape, assault, robbery, vandalism, liquor law, and drug abuse violations among others.
One must also remember that in 2010 Guam had a major crackdown on drunk driving with tougher new penalties (after many years of a very lax policy), and also increased education and awareness about the alcohol problems on the island. Also, the new drinking age of 21 appears to be more heavily enforced that the previous drinking age of 18, which was poorly enforced. That's a lot of variables to consider.
Finally, we should note that if Miron and Tetelbaum's groundbreaking study of the 21 drinking age is any guide, any apparent benefits of Guam raising the drinking age to 21 should disappear beyond the first year or two of adoption. And while tourism actually went up in 2011 (except for Japanese tourists after the tsunami) contrary to our predictions, it is still too soon to say that raising the drinking age to 21 had no adverse effect on tourism. For example, the US military buildup on the island generated increased economic growth that could have potentially masked (or delayed) any declines in tourism that would have otherwise occurred. The Fijian experience is instructive in that it took fully three years for Fiji to see that tourism was suffering due to the 2006 drinking age hike to 21, and then it was lowered back to 18 in 2009.