Tuesday, July 19, 2011

21 Turns 27

This past Sunday, July 17, was the 27th anniversary of the signing of the National Minimum Drinking Age Act.   This was the law that coerced states to raise the drinking age to 21 or lose 10% of their annual highway funding.  It was signed by President Reagan--so much for "states' rights" and "limited government."  Every state except Puerto Rico, Virgin Islands, and (until 2010) Guam had sold out and went with the flow.  We would have though for sure that the southern states would have at least threatened to secede as a result, but money is the roach of all evil.  It was upheld by the highest court in the land when some states decided to fight it, and those states eventually capitulated.   But that was not all--the precedent was set for further federal financial coercion, even when it was not directly related to the funding.  Thus, a piece of America died that day.

One can only hope this un-American law will join the "Forever 27 club."

Let America be America again, and lower the drinking age to 18.  If you're old enough to go to war, you're old enough to go to the bar.  'Nuff said.

Tuesday, July 12, 2011

Things Underage Drinkers Didn't Do (Part 1)

Dave Hitt has a great website, Quick Hitts, with a section titled, "Things Atheists Didn't Do."  It is a list of recent, high-profile cases of the crimes, follies, and misadventures of religious fanatics.  We at Twenty-One Debunked have decided to do something similar.  From time to time, we will post "Things Underage Drinkers Didn't Do", a (partial) list of all the high-profile drunken crimes, follies, and misadventures involving people age 21 and over during the past week or so.  Every case we list occurred in the USA or one of the few other countries where the drinking age is 21, and nearly all cases have no mention of other substances involved.  All suspects are innocent until proven guilty in a court of law.

PART ONE

An underage drinker did NOT "misplace" his baby on the sidewalk after drinking.

An underage drinker did NOT get naked and take a dump in his neighbor's garage.

An underage drinker did NOT kill her teenage son in a drunk-driving crash.

An underage drinker did NOT try to kidnap two teenage girls like this creep did.

An underage drinker did NOT need to be tasered after drunkenly killing a young man and injuring another at 100 mph.

An underage drinker did NOT leave her 3 year old son alone at the pool to get beer money so she could get wasted.

An underage drinker did NOT possibly set a new record for Georgia's highest BAC level (FIVE TIMES the legal limit!) while driving with one's kids in the car in broad daylight.

An underage drinker did NOT drunkenly drive her SUV and smash into a fire station, injuring her teenage daughter who was riding with her.

An underage drinker did NOT get so incredibly wasted that he was completely oblivious that the pedestrian he hit while driving drunk (and landed inside his car) was dead.

An underage drinker did NOT kill a Red Cross volunteer in a drunk-driving crash.

An underage drinker did NOT kill his passenger when he drunkenly sideswiped a train.

The Melrose Place actress who allegedly drove drunk and killed an (almost) elderly New Jersey woman and actually had the audacity to laugh afterwards was well over 21.

Also, none of the police officers recently busted for DUI (one of which drove with his 3 year old son) were underage either.

And that, my friends, is just the tip of the iceberg.

Monday, July 11, 2011

Excellent Alternet Post about the Drinking Age

The recent post on Alternet about the drinking age is probably one of the few (if not the only) occasion the progressive alternative news site wrote an article about this issue.   It is surprising that they don't discuss it more frequently, especially given their very liberal stance on the legalization of other psychoactive substances.  It is truly refreshing to see them be in favor of liberty and justice for all, not liberty for "just us" like some so-called "progressives" and drug-law reformers.

The article, which is clearly in favor of lowering the drinking age, does almost as good a job at debunking the latest Carpenter and Dobkin study as we did back in May.  It also discusses the wisdom of Barrett Seaman, author of Binge: What Your College Student Won't Tell You and current president of Choose Responsibility.  Seaman knows what a failure the 21 drinking age has been, especially on college campuses.  In addition, the article points out just how out of step America is with the rest of the civilized world.

As for the book Binge, while we at Twenty-One Debunked agree wholeheartedly with Seaman's evaluation of the failure of the 21 drinking age and how the law appears to throw gasoline on a fire (so to speak), the author does seem to over-egg the pudding a bit on the other issues he discusses when comparing today's campus life to the way it was in the 1960s when he was in college in upstate New York.  Yes there are kernels of truth in what he says, but we hardly believe that today's students are embroiled in the kind of crisis he appears to suggest they are in.  There is definitely a nostalgia bias at work here.  And while we question whether technology really deserves much of the blame for the apparent "disconnection" he notes, we certainly agree that the 21 drinking age (which artificially and arbitrarily divides members of the college community) certainly isn't helping.

Thursday, June 16, 2011

What is it about July?

July is just around the corner, and we thought you should know some interesting facts about the seventh month of the year.

  • When drinking age laws have been changed in the past, July is the month in which it has historically occured the most.
  • The National Minimum Drinking Age Act was signed into law on July 17, 1984.
  • Wyoming, the last state to raise the drinking age to 21, signed its bill into law on July 1, 1988.
  • The territory of Guam raised its drinking age from 18 to 21 on July 8, 2010, effective immediately.
  • The two most dangerous days of the year in terms of traffic fatalities are July 3 and July 4, despite the fact that the most dangerous month is August.
  • And of course, July 4 is Independence Day in the United States, and July 1 is Canada Day north of the border.

Thursday, June 2, 2011

Latest News Roundup

There have been several relevant news stories lately, including the following:

1)  Scotland, a constituent country of the United Kingdom with a notorious drinking and violence problem, has officially allowed (and is trying to encourage) certain local authorities to locally ban off-premise alcohol sales to 18-20 year olds, while leaving the on-premise purchase age and overall drinking age at 18.  While some welcome the move, others feel it is a backdoor attempt at a blanket ban on alcohol purchase by 18-20 year olds.  But will Scotland Yard* actually enforce it?

2)  The Indian state of Maharashtra, in which Mumbai (formerly known as Bombay) is located, has just raised the drinking age to 21 for beer and 25 for liquor.  Previously, it was 18 for beer and 21 for hard liquor.  However, there is one massive loophole that renders it a joke overall:  there is still no age limit for wine, and there never was before either.  As for enforcement, don't hold your breath:  in Delhi, one of the states where the drinking age has been 25 for years, the law is flouted so much that on a busy night, as many as 90% of bar partons are underage.  They simply don't have the resources or political will to do so.  Ditto for the long-standing law in Maharashtra where anyone who buys alcohol is required to have a permit to do so--almost no one bothers to get one.  In fact, it turns out that the age limit on the books for liquor has already been 25 since 1949--but no one seemed to know it until yesterday!  Currently, out of India's 28 states, there are three that set the drinking age at 18 across the board, two that set it at 25 across the board, three which are totally dry for all ages, and the remainder are either 21 across the board or have a split drinking age like Maharashtra.

3)  New Zealand still has yet to raise the drinking age, as was recently proposed.  But a new report by Sir Peter Gluckman may add fuel to the fire, encouraging the country to raise the drinking age to 21.  Don't worry, though--there's nothing in it that we haven't already debunked before.  Before they even think about raising the drinking age from 18 to 21, perhaps they should actually start enforcing the current law and closing its loopholes.

4)  Apparently Baby Boomers (ages 50-65) in the USA are still drinking too much.  You know, the same generation that hypocritcally denied todays young people the same freedom they had when they were younger.  No surprise there.  Of course, there is always that vexing question of whether they drink so much now because they were allowed to drink at 18 and got hooked more as a result.  If so, there may be some slight justification for their hypocrisy.  However, we at Twenty-One Debunked tested that hypothesis ourselves, using alcohol rehab admission statistics from the SAMHDA database from 1992-2008.  Comparing affected age cohorts in the national data does appear to superficially support that hypothesis, but it falls flat when one notices that there was essentially no difference in such patterns between states that kept the drinking age at 21 (such as California and Pennsylvania) throughout versus similar states that changed their drinking ages (such as New York, New Jersey, and Massachusetts) as well as the nation as a whole.  This is true for both alcohol-specific cases as well as total cases.  Thus, it appears to be a Boomer effect rather than a law effect, and the hypocrisy is not justified in the least.

We at Twenty-One Debunked feel that any attempt to raise the drinking age in any nation is a fool's errand, and will not solve any drinking problems in the long run.  In fact, the focus on 18-20 year olds can lead a nation to ignore the pink elephant in the room.  There has never been any society where adults drink but teens do not, nor has the reverse ever been true.  It's time to stop scapegoating young people for adult problems.

(*That was a test to see if you are paying attention.  Scotland Yard is the headquarters of the London Police Department, which has nothing at all to do with Scotland itself.)

Wednesday, June 1, 2011

A Critique of Carpenter and Dobkin (Part Deux)

We recently debunked a new study by economists Carpenter and Dobkin (2011) that has apparently concluded that lowering the drinking age from 21 to 18 will lead to an 8% increase in deaths among 18-20 year olds and an estimated externality cost of $12 million per 100,000 person years (or $1.44 billion per year), for a combined "social cost" of nearly $10 billion per year.  (There are about 12 million people in that age group.)  The cost estimates were (most ironically) based on the increase in death, injury, and crime that occurs upon turning 21, and the authors suggest that the same would happen for 18-20 year olds if they were allowed to drink legally.  While we believe these estimates are grossly overstated (and most likely just represent delayed rather than decreased costs when the legal drinking age is 21), let us take these estimates at face value for a moment for the purpose of a proper Pigouvian analysis.

First, lets examine the other side of the ledger.  For one, there is the potential 3% increase in wages for each year of education in which alcohol is consumed (versus not consumed), presumably due to increased human and social capital formation.  One study even found that men who go to bars once a month or more make 7% more in wages compared to those who do not--which is significant since under the current laws, most 18-20 year old drinkers do their drinking in locations other than bars.  Since Carpenter and Dobkin estimate that the proportion of drinkers among young adults increases by 6.1 percentage points (or a 10% relative increase) upon being able to drink legally, one could say that, based on per-capita personal income figures for 2009, an economic benefit of roughly $1-2 billion per year in the long run would result from lowering the drinking age to 18.  Tax revenues that fill government coffers (to the tune of $5.6 billion per year for the general population) are another benefit of alcohol, and foregone drinks translate to foregone taxes.  Americans consume 8.4 liters of alcohol per capita, or about 117 billion standard drinks per year in total, making that a tax benefit of about $0.05 per drink.  Since Carpenter and Dobkin estimate that an additional 547 million drinks total will be consumed per year if the drinking age was reduced to 18 (which we strongly doubt, but let's go with it anyway), that would be a benefit of $27 million per year.  However, that only includes excise taxes.  When all taxes are taken into account, beer sales alone bring in about $30 billion per year, so we estimate that total alcohol brings in at least $40-45 billion, or $0.40 per drink.  Using that figure, lowering the drinking age to 18 would yield $219 million to the economy.  The fact that more drinking would occur in bars would only boost that number even higher.  Due to the uncertainty over health benefits of moderate alcohol use for young adults, we exclude them from our calculations.

We also need to examine the externalities of the 21 drinking age itself.  There is the cost of enforcement, of course, which while we don't know the exact number, we do know that states receive $25 million each year from the feds for the purposes of underage drinking enforcement.  Since states most likely spend their own money as well on this effort, this is a lower-bound estimate of the real number, which we believe is probably double that.  But some of these funds would still be spent if the drinking age was 18, so we'll stick with the $25 million figure for now.  We also know that due to the laws' ineffectiveness, numerous other ancillary laws (dram shop, social host, use and lose, keg registration, etc.) are often used to prop up the 21 drinking age.  There are also significant opportunity costs to enforcing all of these laws, so that fewer resources are devoted to real crimes, including violence and drunk driving.  Also, the estimates of the costs of legal alcohol use by 18-20 year olds should be adjusted downward, since forcing alcohol use underground makes it more dangerous than it has to be.  The penalties for those who do get busted can be quite harsh in some states, and when you criminalize normative behavior you also create costs such as an increased number of individuals with criminal records, which limits their job opportunities in the future and hinders their ability to become productive members of society.  There are also increased court costs and increased lawsuits as well.  Other costs, such as loss of social cohesion and loss of civil liberties are probably very high (and many would even say priceless), but exceedingly difficult to measure.  But for now let's estimate all of these total externalities conservatively at, say, $200 million per year.

Looking at both sides of the ledger, lowering the drinking age to 18 would now give a net social cost of $7.5 billion, including a net external cost of $1 billion per year.  However, if we take into account that the increased wages would be taxed as well, the estimate of the net external cost (which is really the only cost that matters for public policy) drops to about $800 million.  And if we use a somewhat smaller value for the statistical value of a life than Carpenter and Dobkin used (there are many legitimate values given in the economic literature), the estimate shrinks even further to as little as $500-750 million.  And if a less conservative estimate of the externalities of the 21 drinking age law, say, $200-500 million (remember the measurement difficulty) and hedonic effects of alcohol are factored in, you're now talking chump change, at least relative to our society's $14 trillion GDP. 

A remaining externality gap of at most a few hundred million dollars could easily be made up by raising the alcohol taxes, especially since this has also been shown in several studies to reduce traffic fatalities and other alcohol-related social ills, especially among young people.  And at least one economist, Donald Kenkel (1993), considers higher alcohol taxes combined with a drinking age of 18 to be more socially efficient than a drinking age of 21.  Raising the tax rates to a level that would increase the price of alcohol by as little as 12% could theoretically be enough.  In another paper published the same year, he also notes that tougher penalties for drunk drivers would be more efficient than a 21 drinking age as well.  And we at Twenty-One Debunked believe that Pigouvian taxation (for all ages) makes far more sense than prohibition of drinking for 18-20 year old young adults.

Remember, as we have noted in previous posts, that we do not believe that Carpenter and Dobkin's estimates are accurate, and that several studies have debunked the claim that the 21 drinking age saves lives on balance, and even the claim that it leads to large reductions in alcohol consumption.  Any reductions that do occur are really just delays.  Thus, since our analysis assumes Carpenter and Dobkin's estimates to be reasonably correct, we still understate the net benefits to lowering the drinking age by a great deal.

A proper Pigouvian analysis of young adult drinking would also consider the marginal social cost (MSC) versus the marginal private benefit (MPB) of alcohol consumption, in this case for 18-20 year olds.  While this is not easy since we have yet to encounter any serious quantitative analysis of these parameters, we at Twenty-One Debunked believe that, as for those over 21, there does exist some level of consumption (which we do not attempt to quantify here) above which MSC exceeds MPB and below which MPB exceeds MSC.  This can be logically inferred from the fact that a heavy-drinking minority cause the majority of the problems associated with alcohol consumption, while most drinkers are non-problem drinkers.  Thus, the goal of public policy should be to reduce alcohol consumption to a socially efficient level via taxation and/or other cost-effective means.

Of course, there are some folks who believe that for people under 21, the most socially efficient level of consumption is zero (i.e. the marginal social cost exceeds the marginal private benefit at all nonzero levels of consumption), making outright prohibition of drinking for that age group the only solution.  We clearly disagree with that statement, but what if it somehow was true?  We know that underage drinking cannot be practically eliminated even under the strictest current regimes, but we could do a thought experiment.  What if, in a relatively Orwellian version of the future USA, our nation decided to fit everyone between the ages of 13-20, inclusive, with a SCRAM bracelet that monitored the alcohol in their sweat 24/7, and then had the bracelet removed upon turning 21?  Costs for all those bracelets, which are currently $300/month/person, would total up to a whopping $90 billion per year.  Even neglecting all other costs to the economy (i.e. lost revenue), transition costs, loss of liberty, and negative hedonic effects, this value would exceed even the most liberal estimate of the total social costs of underage drinking ($60 billion) by $30 billion--a massive net deadweight loss.  Clearly, this is not a viable option by any stretch of the imagination!  And the only other way to guarantee that no one drinks a drop before turning 21 is if no one has kids--which would ultimately lead to our extinction. 

Besides, the cost of "overage drinking", at least in terms of lives lost, is FAR worse than the cost of underage drinking.  That's the pink elephant in the room that the pro-21 crowd doesn't want to talk about.

Let America be America again, and lower the drinking age to 18.  If you're old enough to go to war, you're old enough to go to the bar.  'Nuff said.

Tuesday, May 24, 2011

Latest "Binge Drinking" Study Less than Meets the Eye

Stop the presses!  New study links binge drinking to memory loss in college students!

Now before readers all respond with a resounding "DUH!", we should clarify that the study in question, which looked at 18-20 year old college students in Spain, found that those who admitted to "binge" drinking (six or more drinks in the same occasion at least once a month) performed slightly worse on a test of verbal memory (when sober) than those who did not.  Already the media has taken it and ran with it, with some people inferring that this is evidence of permanent brain damage.  Even worse, some folks have even interpreted this study as justification for the 21 drinking age.  And those lines of reasoning are flawed to say the least, especially when one considers what the study actually found rather than the speculation of the alarmists.

First of all, the actual study was a cross-sectional study, and although it did control for several potential confounders, its design made it impossible to determine whether the link was causal since one could not test for temporal precedence (a crucial criteron of causation), much less truly isolate the drinking from all other variables. Second of all, the size of the effects was small (e.g. the "bingers" remembered 2-4% less information from a story compared to controls), not always statisically significant, and was in all cases within a standard deviation.  For the word list recall, the difference in the number of words recalled was less than a single word.  These differences would be of little to no practical significance, even if they technically were statistically significant.  Third, no gender differences of the apparent effects were noted, despite the fact that women are generally more sensitive to alcohol than men as a rule, and that the definition of a "binge" was not gender-specific.  Fourthly, we know nothing from the study about how long such effects persist, since the participants were only required to abstain from alcohol or drug use for 24 hours, and such abstinence was not monitored.  Hangovers may very well last longer than 24 hours in some cases, which may confound results.  Finally, the study design precluded determination of a dose-response relationship, so the all-important question of "how much alcohol is too much" relating to neurotoxicity remains unanswered by this investigation.

This should remind us all of another relatively recent cross-sectional study of 18-20 year old first-year university students in Spain, that looked at the effects of so-called "binge" drinking on the brain. In this study, 95 students (42 "bingers", 53 controls) were given tests of attention and working memory, and their specific brain waves were monitored with electrodes. No statistically significant differences were observed between the two groups in terms of actual performance, but the electrophysiological test suggested that more attention was expended to complete a given task among the "binge" group, as well as other electrophysiological differences. This is a lot more nuanced and less certain than the media are implying, and hardly represents "dain bramage."   EEG differences were also noted in another recent study of a broader age group of young adults in the United States, but such differences were largely confined to "high-binge" drinkers (10 or more drinks per drinking session) rather than those who had 5-7 drinks per session.

Another recent study, done on 18-20 year old college students in Belgium, also found similar electrophysiological differences, but again no behavioral performance differences for some reason.  In this study, which was one of the very few longitudinal studies on the matter, there were no differences in alcohol consumption or electrophysiological results at baseline, but both changed significantly in the "binge" group when measured 9 months later, but not in the control group. However, we should keep in mind that the binge group averaged 12.5 units (about 9 American drinks) per binge session, and two such binge sessions per week, which is quite extreme. Number of drinks per week averaged a whopping 35 units (25 American drinks) in the binge group, while the control group drank barely even one drink per week. And some participants drank as recently as three days before the tests as well, potentially conflating short and long term effects, though this was ostensibly controlled for. One good thing about this study, however, was that the sample size was significantly larger than the aforementioned one, and due to its longitudinal nature there was both a before test and and after test, enabling us to control for preexisting differences between the two groups. 

The biggest flaw in all of these studies was the fact that there was no over-21 comparison group. So we simply cannot infer anything at all about age from this piece of research. Absolutely zilch. A better method would have been to have three groups each examined separately: 15-17, 18-20, and 21-24 years of age. But no study that we know of meets this standard.  This would help to settle the nagging question of whether or not it actually is worse to drink at 18 rather than 21. Or perhaps some people are afraid of the possibility that their rationale for keeping the drinking age at 21 would be debunked if such a comparison was done. As yet, there is essentially ZERO hard scientific evidence that drinking at 18 is significantly worse than doing so at 21, ceteris paribus, but a plethora of evidence showing that excessive drinking is unhealthy at any age.  Indeed, a 2002 study of alcoholics found no significant differences in the long-term effects on participants' neuropsychological performance with respect to age of onset (before vs. after age 20) of alcohol abuse. And still another study in 2007, this time of 21-25 year olds (you know, folks who are legally allowed to imbibe) who were self-identified heavy drinkers (more than 25 drinks per week), found that subtle brain changes are not exclusive to those under the magic age of 21.

Drinking ludicrous amounts of alcohol is dangerous, period.  Regardless of age. That, if anything, should be the moral of the story. Keeping the drinking age at 21 only encourages such extremes, especially for college students.

We at 21 Debunked provide this for informational purposes only and do not in any way advocate drinking of any kind, underage or otherwise.

Sunday, May 22, 2011

A Critique of Carpenter and Dobkin (2011)

Recently, a new study by economists Carpenter and Dobkin (2011) has apparently concluded that lowering the drinking age from 21 to 18 will lead to an 8% increase in deaths among 18-20 year olds.  The authors argue that those who are proposing lowering the drinking age would therefore face "a very high burden of proof" for their position.  However, there is less to this study than meets the eye, and we at Twenty-One Debunked do not agree with their conclusions.  In fact, much of what the study adds actually can be said to fuel our side of the debate rather than the pro-21 side, and the burden of proof actually falls on them, not us.

The first part of their study separately examines daytime and nighttime traffic fatality rates (from FARS) from 1975-1993 for four age groups:  15-17, 18-20, 21-24, and 25-29.  (Nighttime deaths should be affected much more than daytime ones since the former are much more likely to involve alcohol.) They use a fixed-effects panel regression that, while it controls for state and year fixed effects, state-specific trends, and population changes, still fails to control for any other variables that would not be subsumed under these (in contrast to Miron and Tetelbaum (2009) and Dee and Evans (2001)).  The drinking age was expressed as the proportion of 18-20 year olds who are legal to drink in a given state-year, hence the expected sign is positive.  The results are summarized below as percent changes, with statistically significant values (p < 0.05) in bold:


Age  Group% Change (Night) % Change (Day)
15-177.98.3
18-2016.94.7
21-2411.36.9
25-299.71.7

As one can see, the apparent effect occurred among all age groups rather than just the 18-20 year olds who were targeted by the changes in the legal drinking age.  For 15-17 year olds (the spillover group), whose effects were statistically insignificant, the day-night counterfactual does not appear to work would be predicted if banning 18-20 year olds from drinking really saved the lives of the former.  However, it does appear to work for 21-24 year olds and 25-29 year olds, both of whom should not have been affected by the change in the drinking age since the age groups were evaluated contemporaneously rather than as cohorts.  In fact, the effects on 18-20 year olds and 21-24 year olds are rather comparable, as opposed to a mere spillover which would be much smaller in magnitude.  Thus, it is very likely that the drinking age was a proxy for something else, i.e. one or more of the many possible variables that was not controlled for such as anti-drunk driving campaigns or tougher DUI laws.

We should compare this to other studies that looked at the effects on various age groups.  Miron and Tetelbaum (2009), who thoroughly debunked the idea that the 21 drinking age saves lives (at least in the long run) for 18-20 year olds, found that a legal drinking age higher than 18 has no effect either way on 21-23 year olds but actually increases under-18 driver fatalities.  Dee and Evans (2001) found that a drinking age of 18 or 19 (relative to 21) increases traffic fatalities among 18-19 year olds but decreases fatalities among cohorts of 22-24 year olds who were allowed to drink at 18 or 19, with no consistent effect on 16-17 year olds.  This echoes Asch and Levy (1987 and 1990) and Males (1986), who both found that raising the drinking age to 21 likely just shifts traffic deaths from 18-20 year olds to 21-24 year olds and possibly even increases the net probability of dying by age 25.  In addition, a new, award-winning paper by Dirscherl (2011) finds that raising the drinking age to 21 not only shifts deaths from 18-20 year olds to 21-24 year olds, but actually leads to a net increase in deaths among 18-24 year olds, a phenomenon we like to call "White Noise Syndrome".

Next, the authors examined the effects of the drinking age on the mortality rates of various causes of those same four age groups.  These death rates were gleaned from vital statistics from the National Center for Health Statistics, and the panel estimates of the effects were obtained from a similar model to the one discussed above.  Again, the expected sign is positive.  The results are summarized below, with statistically significant values (p < 0.05) in bold:



Age Group% Change
All-Cause
% Change
Traffic
% Change
Suicide
%Change
Homicide 
%Change
Alcohol
% Change
Other
External
15-175.58.49.36.3-30-4.0
18-206.99.110.1-4.6-109.0
21-245.510.53.7-6.52.511.6
25-29-0.84.40.0-1.9-185.2

We see that only for suicide is the effect statistically significant for 18-20 year olds and at the same time insignificant (and smaller) for the other age groups.  That is, only for suicide can one actually infer a potentially significant lifesaving effect of the 21 drinking age.  For traffic fatalities and other external causes of death, there now seems to be a greater effect for 21-24 year olds than for 18-20 year olds, which casts doubt on whether these effects were actually due to the drinking age.  Interestingly, homicide and alcohol-related deaths (e.g. alcohol poisoning, etc.) were not only statisically insignificant in all cases but even had the "wrong" sign for most of the age groups.  Finally, for all-cause mortality, we see that none of the estimates are significant, not even at the 10% level, which means that they are likely due to chance (and thus spurious).  However, the above results are nonetheless taken by the authors of the study to indicate an overall lifesaving effect.

In a previous post, we at Twenty-One Debunked ran several difference-in-differences analyses on mortality rates of 15-19 and 20-24 year olds for all of the external causes listed above.  Those were the only age groups publicly available through CDC's WONDER database, and while not ideal, taken together they are still useful for generating estimates of the net effects in the long run, which we did.  The control group was the 11 states (excluding Utah) that did not change their drinking ages (i.e. they remained 21 throughout since the 1930s and 1940s), while the treatment group was the states that had a drinking age of 18 in 1979 and later raised it to 21.  Comparing 1998 to 1979, we found that the net difference-in-differences between the groups had the "wrong" sign for nearly every cause of death, especially suicide for 15-19 year olds.  Only for homicide was there an apparent lifesaving effect, but removing New York from the data attenuated this effect to almost null.  The pattern for suicide vs. homicide appears to be the reverse of what Carpenter and Dobkin found.  Overall, we found no net lifesaving effect in the long run, echoing what Miron and Tetelbaum found for traffic deaths, and thus perhaps Carpenter and Dobkin's results are primarily capturing short-term effects due to the study design.

Next, the study's authors discuss their previous work on regression discontinuity estimates using more recent data, which we critique here.  This analysis shows a discrete and significant jump in mortality at exactly age 21.  The effect is true only for external causes of death, including motor vehicle accidents, suicides, deaths labled as "alcohol related," and those labeled as "other external," but not homicides or drug-related deaths.  Another similar study they did concerning various types of crime gave similar results overall.  But unfortunately, they also make the specious claim that such an effect is not merely a delay in deaths, but rather constitutes a true lifesaving effect of the policy (which is dubious).  In any case, it certainly shows once and for all that there is nothing at all about turning 21 that magically makes one a safe responsible drinker.

The authors then tie together all of their analyses thus far, and assert that despite all of these limitations, the similarity of the effect size (8-10%) between the regression discontinuity analyses and the panel estimates implies that the effects of the 21 drinking age are likely to be truly causal rather than a proxy for something else.  We find that argument to be puzzling at best, especially since Miron and Tetelbaum also found a similar effect of MLDA-21 (8-11%) in their initial 50-state model relative to MLDA-18, but it nonetheless dropped well below statistical and practical significance when the states were disaggregated and when the persistence of the effect was analyzed.  For some states, it apparently even made things worse.  Thus, an effect of this size may very well be a mirage rather than a truly causal relationship.

But the most tenuous aspect of the author's latest study is their analysis of the "social costs" in dollars per drink consumed by people under 21 if such drinking was legalized.  Not only do they presume that the effects they observed in the aforementioned analyses are causal and represent a net lifesaving effect of the 21 drinking age, which we doubt, they also leave out much of the other side of the ledger with respect to alcohol consumption by ignoring or dismissing several potential economic benefits associated with it.  They also ignore the likely adverse effects of a high drinking age on social cohesion, as well as the fact that forcing alcohol use underground makes it far more dangerous than it has to be, to say nothing of the value of individual liberty.  And the by the same measures, the social cost per drink would likely be at least as high for people over 21 on balance, especially 21-24 year olds who are the most likely of any age group to drive drunk (both in the USA as well as countries with lower drinking ages).  Using their logic, even bringing back Prohibition could potentially be justified, and we all know how well that worked out. 

On balance, the 21 drinking age is an EPIC FAIL.  And even more so are the tired, old attempts to justify it.

QED

Saturday, April 30, 2011

Spot the Difference (in Differences)

The pro-21 crowd insists that the 21 drinking age saves lives.  In fact, they even claim to know the number of lives it saves each year:  about 900 fewer traffic deaths per year.  However, that figure is based on rather questionable assumptions.  And in this post, like in previous ones, we seek to demolish these faulty conclusions.

TRAFFIC DEATHS

Take a look at the graph below.  We have accessed the CDC's WONDER database, a publicly available health statistics database which has mortality data going back to 1979.  The graph contains all deaths among 15-19 year olds and 20-24 year olds that were labled as "motor vehicle traffic" fatalities.  All deaths are per 100,000 people.

National

As avid readers of this blog can recall, the drinking age was 18 or 19 in most states in 1979, and was 21 in all states by 1988.  Thus, in the aggregate, it seems like there was some lifesaving effect.  But as Mark Twain observed, "there are lies, damned lies, and then there are statistics".  One thing you can probably see right off the bat is that the decline in deaths had begun in 1979-1980, well before the 1984 federal law that coerced states to raise the drinking age to 21.  However, several states also raised their drinking ages voluntarily before that:  usually to 19, but a few raised it to 20 or 21 by 1983.  So we need to dis-aggregate the data to see whether or not there was any lifesaving effect.

We have separated the states into "control" and "treatment" groups to do a difference-in-differences analysis on the above data.  There were twelve states that did not change their drinking ages at all since the 1930s and 1940s (Arkansas, California, Indiana, Kentucky, Missouri, Nevada, New Mexico, North Dakota, Oregon, Pennsylvania, Utah, and Washington), remaining 21 throughout, and these form our control group.  (We omitted Utah since that is a special case due to their high Mormon population and archaic alcohol laws in general).  For the treatment group, we included every state that had a drinking age of either 18 or 19 for at least a portion of the time period 1979-1998.  All other states (Delaware, Maine, Michigan) were excluded entirely since they had a drinking age of 20 or higher since January 1, 1979.

Control Group

Treatment Group

In addition, we then modified the treatment group to exclude all states that had a drinking age higher than 18 as of January 1, 1979.  All states that are included had a drinking age of 18 at some time.

Treatment-18 Group

Funny how similar all three graphs look, despite the differences in the drinking ages.  The difference-in-differences analysis between the control and treatment-18 groups is shown below:

Control, 15-19:  -46.5%
Treatment, 15-19:  -39.2%
DD:  +7.3%

Control, 20-24:  -49.5%
Treatment, 20-24:  -40.1%
DD:  +9.4%

Wow, that sure seems like a perverse effect of the 21 drinking age!  The treatment group saw less progress overall than the control group, and they started out lower as well.  This was true even more so for the 20-24 age group.  Of course, an even greater lack of progress is evident in the 25-34 age group:

Control, 25-34: -49.5%
Treatment, 25-24: -34.2%
DD:  +15.3%

What would our difference-in-differences analysis look like if we used the ratios of 15-19 and 20-24 year old fatalities to those in the 25-34 age group, as opposed to absolute fatality rates?  The following calculations show what would happen to our results:

Control, 15-19 ratio: +5.8%
Treatment, 15-19 ratio: -8.0%
DD:  -13.8%

Control, 20-24 ratio:  0%
Treatment, 20-24 ratio:  -9.2%
DD:  -9.2%
 
So, does this mean there is a net lifesaving effect after all?  Hardly!  There could be any number of reasons why the rates of progress differed between 15-24 year olds and 25-34 year olds.  Take another look at the graphs above.  We see that most of the fatality decline has occurred by 1992, and we also know that there was no change in the drinking age from 1990 onwards (the first full year that no grandfathered 18-20 year olds could drink legally).  Thus, we now restrict our ratio DD analysis to 1979-1992:
 
Control, 15-19 ratio:  -6.5%
Treatment, 15-19 ratio:  -3.7%
DD:  +2.8%
 
Control, 20-24 ratio:  -0.1%
Treatment, 20-24 ratio:  -11.3%
DD:  -11.2%

Thus, it does not appear that the 21 drinking age had a real lifesaving effect.  The results of the 1979-1992 ratio DD analysis are totally in the wrong direction:  20-24 year olds should be only minimally affected by an increase in the drinking age to 21, yet they appeared to "benefit" (likely by chance) when we control for the relative lack of progress among 25-34 year olds in the treatment group, while the 15-19 age group saw a relative increase in deaths.  Omitting Louisiana (a state who had a massive loophole in the 21 law well into the 1990s) and states that had a drinking age for only a portion of 1979 did not substantially alter the results.  Unfortunately, we could not separate the data into 18-20 and 21-24 age groups, nor could we distinguish between alcohol-related and non-alcohol-related deaths.  However, the 15-19 year old group includes those most affected by a drinking age of 18 or 19 as well as the so-called "spillover" group of 15-17 year olds, and only one-fifth of the 20-24 year old age group would be directly affected by raising the drinking age to 21.  Also, not all "alcohol-related" crashes are necessarily caused by alcohol, and differences in reporting and testing can bias the results in either direction.  Thus, our general conclusions remain valid.

New York

Here we see New York, a state whose drinking age was 18 since 1934, raised to 19 in December 1982 voluntarily and then to 21 in December 1985 under federal duress.  In NYC, where nearly half of the state's population lives, the drinking age remained unenforced for the most part until Rudy Giuliani became mayor in 1994.  One can see that the decline in traffic fatalities began since 1980, years before the drinking age was raised, and seemed to decline at a slower rate after the drinking age was raised to 21.  The decline then resumed a few years later, but stalled again since 1994 when NYC began enforcing the 21 drinking age more strictly.  One can also clearly see this when you look specifically at fatalities in teen drunk-driving crashes since 1982.  Thus it is far from obvious that the 21 drinking age had any benefits at all as far as reducing traffic fataltites.

Now, see if you can guess what year the following, unnamed state raised its drinking age.  Go on, guess.


The answer is that they didn't!  The state shown, California, has had a drinking age of 21 since 1933, yet its graph still seems to resemble the national graph as well as New York's.  And if you look closely at the graphs, you'll see that New York was actually making more progress than California until 1985, after which the reverse was true.  Gee, what could have happened?

"ALCOHOL-RELATED" TRAFFIC DEATHS

While the CDC WONDER database does not separate out alcohol-related ones, NHTSA's FARS database does.  While not all this data is publicly available, some of it is.  Taken from a NHTSA paper, we look at the state-level experience of changes in alcohol-related fatalities involving a 16-20 year old driver from 1982-1998.  Since there are no reliable data before 1982, we define our control group as all those who had a drinking age of 21 for several years before 1982 (including Michigan and Utah this time) and our treatment group as those whose drinking ages were 18 for at least a portion of 1982.

Control, median:  -64.3%
Treatment, median:  -68.6%
DD:  -4.3%

At first glance. it looks like there might indeed be a lifesaving effect, even if it is a small one.  But what if we omit those states that had a drinking age higher than 18 for a substantial portion (i.e. more than one month) of 1982? 

Control, median:  -64.3%
Treatment, median:  -64.1%
DD:  +0.2%

Thus, we see the effect was spurious.  This further contradicts the claim that the 21 drinking age saved lives.

NON-TRAFFIC DEATHS

But what about non-traffic fatalities, such as alcohol poisoning, falls, violence, suicide, and alcohol-related diseases?  We also calculated those as well:
 
Alcohol-related deaths* (1979-1996)
 
Control, 15-19:  -82% (unreliable)
Treatment, 15-19: -60%  (unreliable)
DD:  +22%
 
Control, 20-24:  -39%
Treatment, 20-24:  -62%
DD:  -23%
 
Control, 25-34:  -33%
Treatment, 25-34:  -47%
DD:  -14%
 
*Includes all deaths labeled with "alcohol" in the cause of death.  Since the number of deaths is small, any year with fewer than 20 deaths is labled as "unreliable".
 
Suicide (all kinds, 1979-1998)
 
Control, 15-19:  -12%
Treatment, 15-19:  +10%
DD:  +22%
 
Control, 20-24:  -21%
Treatment, 20-24:  -22%
DD:  -1%
 
Control, 25-34:  -27%
Treatment, 25-34:  -20%
DD:  +7%
 
(Perhaps Alex Koronay-Palicz was right about the loss of social cohesion leading to more suicides as a result of the 21 drinking age.)

Homicide (all kinds, 1979-1998)*
 
Control, 15-19:  +17.9%
Treatment, 15-19:  +3%  (+15.2% excluding NY)
DD:  -14.9% (-2.7% excluding NY)
 
Control, 20-24:  -4.8%
Treatment, 20-24:  -12.3% (-7.8% excluding NY)
DD:  -7.5% (-3.0% excluding NY)
 
Control, 25-34: -40.1%
Treatment, 25-35: -41.0%  (-38.4% excluding NY)
DD:  -0.9% (+1.6 excluding NY)

*Interpret with caution; California (a control state) saw declines of -3.5% and -19.3% for 15-19 and 20-24 year olds, respectively.
 
Unintentional Injury (all kinds, including traffic, 1979-1998)
 
Control, 15-19:  -48.8%
Treatment, 15-19:  -41.3%
DD:  +7.5%
 
Control, 20-24:  -47.8%
Treatment, 20-24:  -41.9%
DD:  +6.9%
 
Control, 25-34:  -40.0%
Treatment, 25-34:  -33.0%
DD:  +7.0%
 
All Causes of Death (1979-1998):

Control, 15-19:  -33.7%
Treatment, 15-19:  -28.4%
DD:  +5.3%

Control, 20-24:  -31.8%
Treatment, 20-24:  -29.2%
DD:  +2.6%

Control, 25-34:  -25.5%
Treatment, 25-34:  -20.3%
DD:  +5.2%

Thus, it appears to be a wash overall at best, or even perverse at worst.  In nearly all cases, 15-19 year olds see less progress in the treatment states relative to the control states and/or less progress relative to 25-34 year olds.  If that's success, we'd hate to see what failure looks like.

Friday, April 22, 2011

America's Best-Kept Secret

What is America's best-kept secret of all?  According to traffic safety researcher Leonard Evans, the "secret" is a rather open one--our lack of progress in reducing traffic fatalities relative to other industrialized nations.

While it is true that our nation has made progress over the past few decades, such progress has been abysmal compared to that made by Canada, Australia, the UK, and most of Europe.  Take a look at the following table:

CountryMLDA1979 Fatalities2002 Fatalities% Change
(raw)
% Change
(per vehicle)
% Change
(per VMT)
USA2151,09342,815-16.2%-46.2%-52%
UK186,3523,431-46.0%-67.1%-70%
Canada18 or 195,8632,936-49.9%-63.5%N/A
Australia183,5081,715-51.1%-79.1%N/A

In other words, if we had kept pace with the other nations listed, there would have been an additional 200,000 lives saved from 1979-2002.  If we were to grade these countries, Australia would get an A, the UK and Canada would each get a B, and the USA would get a D.

There are likely several reasons why America is lagging behind, of course.  But one of the most notable ways in which the USA differs from the rest is our ludicrously high drinking age of 21, compared to 18 in most other countries.  So let's take a look at younger drivers, using data from the latest IRTAD report:

CountryMLDA% Change
15-17 (raw)
1980-2009
% Change
18-20 (raw)
1980-2009
% Change
21-24 (raw)
1980-2009
% Change
15-17 (p/c)
1990-2008
% Change
18-20 (p/c)
1990-2008
% Change
21-24 (p/c)
1990-2008
USA21-68%-59%-56%-50%-34%-29%
UK18-88%-72%-61%-53%-50%-53%
Canada18 or 19N/AN/AN/A-55%-49%-50%
Australia18N/AN/AN/A-50%-59%-57%
New Zealand18-52%-63%-58%-66%-68%-75%

We see that America lags behind the rest of the countries for younger drivers as well.  We added New Zealand to the list because that was a country that not only did not raise the drinking age, but actually lowered it from 20 to 18 in 1999.  Unfortunately, the IRTAD report did not give age-specifc data before 1990 for Canada and Australia, nor did they give age-specific data for alcohol involvement for any country.  However, the post-1990 data are still useful despite the constant drinking ages, as enforcement of the 21 drinking age did increase during that time in the USA.

When one looks at the report, one can see that since 1990, most of the progress involving the youngest drivers in America occurred after 2005, during a time when gas prices soared.  Thus, we now see what the numbers look like when the data are truncated to 1990-2005.  We also examine 1998-2008, the most relevant ten-year period to NZ since they lowered their drinking age to 18 in 1999.  All rates shown below are per-capita.

CountryMLDA% Change
15-17 (p/c)
1990-2005
% Change
18-20 (p/c)
1990-2005
% Change
21-24 (p/c)
1990-2005
% Change
15-17 (p/c)
1998-2008
% Change
18-20 (p/c)
1998-2008
% Change
21-24 (p/c)
1998-2008
USA21-35%-16%-18%-40%-22%-13%
UK18-40%-32%-35%0%-35%-35%
Canada18 or 19-43%-38%-38%-31%-24%-23%
Australia18-50%-49%-39%-31%-24%-22%
New Zealand18-41%-53%-72%-35%-32%-19%


This table appears to confirm what we suspect.  Before the massive gas price rise of the late 2000s, (which appears to have stronger effects on younger people for some reason), America lags the other nations even more so.  We even lag behind New Zealand of all countries!  Due to America's lower gas taxes and prices at baseline, the percent difference in gas prices (twofold from 2004 to 2008) was significantly larger than for the other nations--and Americans are not used to high gas prices ($4.00/gallon is considered "low" in Europe, and "high normal" in Canada).  As for NZ, it does not appear that lowering the drinking age led an increase in deaths relative to comparable countries (especially Australia) that kept the drinking age constant, at least not in the long run. 

So why did American 15-17 year olds see significantly more progress than their slightly older counterparts since 1990, despite lagging behind 15-17 year olds of several other countries?  During the gas price rise, one can easily see why since that age group simply has less money to spend on gas.  And while they saw more progress than their older counterparts before the price rise, that is likely due to the increase in graduated driver licensing programs in the USA.  New Zealand already had graduated licensing since the late 1980s, while the USA and Canada generally implemented it in the late 1990s.  The main difference between the American version is that it generally applies only to drivers under 18, while in the other countries it applies to all novice drivers (or at least all novices under 20 or 25).  Also, the American version tends to have tighter restrictions on those to whom it does apply, especially when it comes to passengers.  This can lead to fewer deaths among 15-17 year olds simply by encouraging them to "wait it out" until 18, when they can get an unrestricted license despite the fact that they are no better at driving than they were two years prior.  And those that do begin driving at 16 or 17 would do so under less realistic conditions.  One study actually found a shifting of deaths to 18-19 year olds as a result of California's GDL program that started in 1998--and a net increase in total 16-19 year old fataltities.

But what about alcohol-related traffic fatalties?  In a previous post, we have already compared the USA and Canada--see the following graphs of the most relevant time period, courtesy of NHTSA:


Percent Change from 1982-1997
US: drivers age 16-20 in fatal crashes with positive BAC (FARS)
Canada: driver fatalities age 16-19 with positive BAC (TIRF)
Percent Change from 1982-1997
US: percentage of drivers age 16-20 in fatal crashes with positive BAC (FARS)
Canada: percentage of driver fatalities age 16-19 with positive BAC (TIRF)

Interestingly, the decline in alcohol-related traffic fatalities since 1982 occurred at about the same rate in both countries, with no evidence of divergence in the expected direction despite the fact that Canada did not raise the drinking age to 21.  In both countries, drivers under 21 saw some of the largest declines of all compared with other age groups, though all ages saw some decline over the long run.  Moreover, progress continued for Canadian teens from 1997-2005, while unfortunately it stalled for their American counterparts during that time, only resuming after gas prices began to skyrocket and the economy began to sag.  And yes, gas prices do have an effect on alcohol-related crashes.  In 2005-2006, the rate of total 15-24 year old traffic fatalities (per 100,000 people) for the USA was 25.5, and 16.9 in Canada, the latter being 33% lower than the former. 

For the number of all-ages "alcohol-related" fatalities, MADD's own statistics show that from 1982-2004, it declined a whopping 62% in Canada, while it only dropped by 36% south of the border.  And unlike Canada, much of America's "progress" since 1993 was rather hollow in that the decrease in the percentage of deaths that were "alcohol-related" was primarily a result of an increase in non-alcohol related fatalities since that year.  If that's success, we'd hate to see what failure looks like.

Looks like Jack Smith, president of the Canada Safety Council, was right when he said that (relative to Canada), “It’s hard to see how anyone could cite the American experience as a success" when asked whether Canada should raise its drinking age to 21.  And we at Twenty-One Debunked certainly agree.  We really need to see the forest for the trees.