When Alcohol Retreats, Cannabis Advances (And Vice-Versa)

A number of studies suggest that alcohol and cannabis (marijuana) are economic substitutes, meaning that when one increases, the other tends to (albeit unequally) decrease.  The past five years are one example of such opposing trends.  Thus, one apparent unintended consequence of raising the drinking age to 21 was a modest increase in cannabis use among 18-20 year olds and high school seniors.

The most recent study by Crost and Guerrero (2011) found that, using a regression discontinuity approach, upon turning 21 young adults tend to increase their drinking and decrease their cannabis use, both in terms of probability and frequency.  The authors estimate from this pattern that the 21 drinking age law decreases past-month alcohol use by 16% while increasing past-month cannabis use by 10% among 18-20 year olds.  The apparently larger effect size for alcohol may reflect greater reporting bias of drinking (which is illegal before 21 but legal afterward) relative to cannabis use (which is illegal for all ages), so the real effect on alcohol may be considerably smaller.  This study dovetails nicely with an older study by DiNardo and Lemieux (2001), which found that raising the drinking age to 21 in the 1980s led to a decrease in self-reported alcohol use accompanied by an increase in self-reported cannabis use by high school seniors, though both effects were fairly small.  It also dovetails somewhat with the webmaster's own (albeit unscientific) observations of his peers' behavior in high school and especially college.

Further evidence for substitution effects can be found in another recent study by Anderson and Rees (2011).  This study found that legalization of medical cannabis was associated with a modest increase in self-reported cannabis use among young adults aged 18-25 (but not among people under 18) and a modest decrease in alcohol sales and consumption.  Even more notably, legalization of medical cannabis was associated with a 9% decrease in traffic fatailites, which was most likely a result of reduced alcohol consumption.  Also, the same DiNardo and Lemieux study mentioned before found that state-level decriminalization of cannabis was associated with a decrease in drinking among high school seniors, even though there was no corresponding increase in cannabis use (actually, both went down).  Interestingly, in contrast to the effects of the drinking age, higher beer taxes were found to reduce both alcohol and cannabis use.

So is this apparent substitution effect of the 21 drinking age a good thing or a bad thing?  While it is true that unadulterated cannabis is generally safer than alcohol by just about any objective measure of harmfulness, neither substance is absolutely safe for everyone, and most of the pro-21 crowd would probably not be very thrilled about an increase in cannabis use.    Furthermore, reporting bias may very well overstate the effects of the drinking age on alcohol (but not cannabis) use, and thus the net effect is uncertain.  Even though probability and frequency of drinking may be reduced somewhat by a 21 drinking age, the intensity of the clandestine drinking that remains may very well increase to more dangerous levels for a variety of reasons.  More ominously, though there have been no direct studies to our knowledge of the effects of the drinking age on hardcore drug (cocaine, heroin, methamphetamine, etc.) or prescription drug abuse among teens and young adults, it is nonetheless plausible that there may be some substitution of those more dangerous substances for alcohol as well.  After all, the crack epidemic of the late 1980s and early 1990s roughly coincided with the drinking age being raised to 21, and the more recent increase in prescription drug abuse coincided with increasingly tougher enforcement of the 21 drinking age.  And while the gateway drug theory is largely a bogus concept, as long as cannabis remains illegal, users will continue to expose themselves to dealers who may also be peddling more dangerous wares.

While Twenty-One Debunked does not take an explicit position on whether cannabis should be legalized, it should be noted that our parent organization, the True Spirit of America Party (TSAP), fully supports cannabis legalization for all adults 18 and over.  And Twenty-One Debunked believes that, if and when cannabis does become legal, the age limit should be 18 rather than 21, for many of the same reasons that we believe that the drinking age should be lowered to 18.

The Invisible Knapsack

Two decades ago, Wellesley College professor Peggy McIntosh coined the term "invisible knapsack" to refer to the subtle and not-so-subtle advantages that come with white privilege and male privilege resulting from inequality.  She describes such privilege as being "like an invisible weightless knapsack of special provisions, maps, passports, codebooks, visas, clothes, tools and blank checks".  The idea is that while we are generally taught that racism and sexism put some people (i.e. women and people of color) at a disadvantage, we are often taught to remain blissfully unaware of its corollary advantages that accrue to white males.  Hence, the "invisible knapsack" of privilege.

We at Twenty-One Debunked couldn't help but notice just how much this metaphor also relates to America's 21 drinking age and the "over-21 privilege" that results.  Being well over 21 myself, as the webmaster and founder of Twenty-One Debunked I have put together a list of advantages in the invisible knapsack of over-21 privilege that people like myself carry every day.  As a person over 21, as long as I have an ID to prove it:

1. I can buy alcoholic beverages at any store that sells them, in any quantity I wish.
2. I can enter pretty much any bar or nightclub of my choosing without fearing that people of my age group cannot get in or will be mistreated in the places I have chosen.
3. If I do not want to associate with people under 21, I may frequent numerous establishments that ban younger people from entering.
4. I am never asked to speak for all of the people in my age group, nor do I have to worry about my individual behavior reflecting on my entire age group.
5. I can legally host a drinking party with my friends, as long as all the guests are over 21.
6. I can join my co-workers for happy hour after work, and even talk about it at work, without any sort of shame.
7. When I go out with people under 21, it is generally understood that one (or more) of them will be the designated driver instead of me.
8. Generally speaking, I can drink alcoholic beverages fairly openly without having to worry about getting arrested, fined, jailed, expelled, having my driver's license revoked, or being publicly humiliated.
9. As long as I am not driving, I can legally get as drunk as I please in many states. 
10. Even in states where public drunkenness is technically illegal, the cops are unlikely to arrest me unless my behavior is really out of control.
11. If I get in alcohol-related trouble on campus, I will likely face lesser penalties, and I will not have to worry about my parents being notified without my consent.
12. If I think one of my peers may have alcohol poisoning, there would be no reason for me to hesitate to call 911 for fear of the law (and vice-versa).
13. I can have a drink or two (or maybe even three!) before driving without having to worry about being over the legal limit for DUI.
14. Even if I drive while over the limit, I can be assured that drunk drivers in my age group will NOT be the highest law enforcement priority.
15. If I choose to drive drunk, I can know that I am statistically more likely to kill someone under 21 than the other way around.
16. Even if I had several convictions for DUI or drunken violence, I can rest assured that I will still be allowed to buy and consume alcohol.
17. I enjoy less scrutiny over my own behavior, because I live in a society in which young people are scapegoated for adult problems.
18. I do not have to worry about being a good role model when it comes to drinking, since people under 21 can be punished (often severely) for emulating me.
19. Finally, I have a much better chance of being taken seriously on the issue of lowering the drinking age, without being accused of selfishness or immaturity.

And the list goes on.  As we see, the 21 drinking age is not just about disadvantaging people under 21, but giving unearned advantages to people over 21 as well.  And while some of these advantages are positive rights that should be extended to everyone (or at least all adults over 18), others are not "rights" at all, but wrongs that are an unfortunate byproduct of setting arbitrary age limits and of adultism in general.  Still others could be considered either rights or wrongs depending on the context.  And let's not forget the luxury of being able to ignore the issue entirely.

So, are the advantages found in this invisible knapsack really worth it?  Many people over 21 would say yes, but upon closer examination these advantages actually come at a hefty price, even for people over 21.  Just think about social host liability laws, other annoying ancillary laws, millions of tax dollars wasted on enforcement, loss of social cohesion, and precedent that can be used to make our supposedly free country even more of a police state.  In fact, the only people over 21 who, on balance, really benefit from the status quo are the ones who least deserve to benefit--those who drive drunk or otherwise behave irresponsibly when it comes to alcohol, as well as those parents who would rather stick their heads in the sand than teach their kids how to drink responsibly.

Do you hear that?  That's (hopefully) the sound of the pro-21 crowd throwing up all of the proverbial Kool-Aid they drank long ago.

2022 UPDATE:  Ten years after writing this, we felt the need to update this list to also include tobacco and cannabis well.  The smoking age for the former was raised to 21 in recent years, and all the states that legalized cannabis set the age limit at 21 as well.

Do Movies Drive Adolescents to Drink?

Just in time for the new movie Project X, a new study comes out that suggests that movies with scenes of alcohol consumption apparently leads to more "binge" drinking among teenagers.  The cross-sectional study, conducted in six European nations (Germany, Iceland, Italy, Netherlands, Poland, and Scotland) did in fact find a statistically significant correlation in five of the six countries, and the mainstream media are really eating it up.

However, correlation is not the same as causation.  Famous 18th century philosopher David Hume's criteria for causation requires three criteria:  1) association (correlation), 2) temporal precedence (which came first), and 3) isolation (from all potentially confounding variables).  While the first one was found, the second was not (a cross-sectional study can never determine temporality), and while the third one was attempted, it is very difficult to do in practice, especially with a single study.   So, even the authors concede that the study does not in itself prove causation due to the lack of data on temporal precedence, which really is the sine qua non of causation.  And while criterion #3 (isolation) is arguably a very stringent standard to apply, this study doesn't even meet many of the Bradford-Hill criteria favored by epidemologists.   So we have good reason to be skeptical of this study.

Due to the lack of data on temporality, reverse causation remains a plausible explanation (i.e. “binge” drinkers are more likely to prefer to watch movies about drinking and partying like Animal House, Van Wilder, Superbad, and the new Project X rather than the other way around). And there is always the possibility of residual confounding.  Interestingly, the study only looked at whether participants ever consumed 5 or more drinks in an evening, not whether they currently do or how often.  Also, one of the countries (Iceland) saw no significant association (in fact, it had the "wrong" sign) after adjustment for confounders.  But we at Twenty-One Debunked must point out even if the relationship is truly causal, it does not follow that censorship is the answer.   Better education about both alcohol AND media literacy seems to be a better solution for a country that is supposed to be a free society.

In the USA and Canada (neither were included in the study), we know that self-reported teen drinking and “binge” drinking (except perhaps for American college students) has significantly declined in the past decade or so in spite of the apparent increase in these types of movies.  In fact, high school drinking is at a record low in both countries as of 2011.  In a similar vein, teen pregnancy rates in the USA, though still the highest in the industrialized world, are also at a record low despite the fact that TV and movies today are by far the raunchiest in history.

Perhaps we should listen to the wisdom of sociologist Mike Males.