Thursday, April 29th, 2010
Reasons to keep the drinking age at 21: Since the drinking age in New Jersey was raised to 21, the number of young people killed in drunk driving crashes has dropped nearly 78%. Need we say more…
I’ve stared at this claim numerous times, while being carried hither and tither by PATH. In it, MADD, the non-profit that took its name from Alhazred’s infamous Acronomicon (A Complete Reference Of Nerdy Or Maximally Impossibly Convoluted Organization Names) is trying to rally support for their cause, and they’re doing it in a way that makes my number sense go off. To the Mathcave!
First: they don’t tell us what they base their numbers, excuse me, what they base their number on. 78% of what, taken from which source, and calculated how? I realize it’s just a small subway ad, but it does manage to mimic a statistical claim quite well. Which it frankly isn’t. It’s an unfounded and barely even meaningful assertion.
Second, they don’t mention when exactly this raising of the drinking age happened, do they? It happened way back in 1982. In the 28 years since, the number of fatal accidents overall might have dropped considerably. Given the safety advances since then, it’s a fair bet it has. If it had dropped by as much as 80%, the number MADD gives us for drunksters would be merely the average drop. The same were true if just the number of young people on the road, or the number of young involved in any kind of crash, had dropped by 80%. In fact, there is a whole host of variables that a claim like this one needs to be controlled against for it to have meaning.
Third, the drop is in “young people killed in drunk driving crashes”. Sounds like that also includes crashes caused by drunk adults. Which are irrelevant to the question of drinking age.
And fourth, how many saved lives do those 78% actually correspond to, and what fraction are they of the total number of young people killed in traffic accidents? If both were small numbers, would the good of the few really outweigh the good of the many here? While this argument assumes there is a net benefit from getting drunk, which itself may seem debatable, there is no foregone conclusion either way. Not allowing people under 21 to drive at all would make their fatalities drop even further, yet I don’t envision that implemented any time soon. The cost would be too high.
Just to be clear: I think drunk driving is irresponsible and stupid at any age, and young people, especially males, are much more likely than the average to do it. They can’t help it, their frontal lobes are hormonal mush. But whether or not raising the drinking age lowers the risk is an empirical question that deserves proper treatment. Mothers, do not mislead us! It makes us SADD (Scientists Against Data Distortion).