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)
15-17	7.9	8.3
18-20	16.9	4.7
21-24	11.3	6.9
25-29	9.7	1.7

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
15-17	5.5	8.4	9.3	6.3	-30	-4.0
18-20	6.9	9.1	10.1	-4.6	-10	9.0
21-24	5.5	10.5	3.7	-6.5	2.5	11.6
25-29	-0.8	4.4	0.0	-1.9	-18	5.2

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

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.

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:

Country	MLDA	1979 Fatalities	2002 Fatalities	% Change (raw)	% Change (per vehicle)	% Change (per VMT)
USA	21	51,093	42,815	-16.2%	-46.2%	-52%
UK	18	6,352	3,431	-46.0%	-67.1%	-70%
Canada	18 or 19	5,863	2,936	-49.9%	-63.5%	N/A
Australia	18	3,508	1,715	-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:

Country	MLDA	% 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
USA	21	-68%	-59%	-56%	-50%	-34%	-29%
UK	18	-88%	-72%	-61%	-53%	-50%	-53%
Canada	18 or 19	N/A	N/A	N/A	-55%	-49%	-50%
Australia	18	N/A	N/A	N/A	-50%	-59%	-57%
New Zealand	18	-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.

Country	MLDA	% 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
USA	21	-35%	-16%	-18%	-40%	-22%	-13%
UK	18	-40%	-32%	-35%	0%	-35%	-35%
Canada	18 or 19	-43%	-38%	-38%	-31%	-24%	-23%
Australia	18	-50%	-49%	-39%	-31%	-24%	-22%
New Zealand	18	-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.

Will Alaska Lower the Drinking Age for the Troops?

Recently, Rep. Bob Lynn of Alaska has a bill to lower the drinking age to 18 for U.S. military members in Alaska.  While we at Twenty-One Debunked believe that all 18-20 year olds, soldier or civilian, should have the same rights that 21 year olds currently enjoy, this is a great first step in the right direction.  The idea certainly deserves a 21-gun salute.

As for military bases, we also have mentioned last year that several military leaders support allowing 18-20 year old servicemembers to drink beer and wine on base.  The current federal law on the matter is that the age limit for drinking on base must be the same as the surrounding jurisdiction or higher (21 in all 50 states, DC, and now Guam), except when within 50 miles of Canada or Mexico.  Fort Bliss (El Paso, Texas) was the last base on mainland U.S. soil to raise their own drinking age to 21 in May 2008.  However, Maj. Gen. Dana Pittard has been considering lowering it back to 18 on base as well.  And of course MADD had to chime in with their usual junk science and scare tactics.

Fort Bliss provides a good modern natural experiment for the effects of changing the drinking age, since that base was an "island" of a lower drinking age in a sea of a higher one, yet only applied to soldiers stationed there.  So what were the results of this experiment?  Well, the DUIs involving soldiers (on and off base) were as follows:

2005:  107
2006:  143
2007:  97
2008:  214
2009:  183

As you can see, there were actually more DUIs after the drinking age was raised than there were before!  That's hardly a ringing endorsement for the 21 drinking age.  While the population of soldiers grew dramatically during that time, it has been growing since 2005, and DUIs were relatively flat or declining until 2008.  Perhaps it was safer to let them drink on base after all, as driving would not be necessary.  As for other statistics specifically involving alcohol and soldiers in El Paso, there are no reliable data either way.  Total traffic fatalities (all ages) in the city, even per capita, were higher in 2008 and 2009 than in in 2006-2007 despite declining for years in the rest of Texas and the nation as a whole.  And while overall crime did decline in El Paso since 2008, this trend predates the raising of the drinking age on base.

While alcohol abuse is indeed a problem in the military (and among civilians), it is a problem for those over 21 as well.  And there does not seem to be any hard evidence that pre-2008 Fort Bliss was any worse than the other bases where it has been 21 for decades.  Thus it does not appear that scapegoating 18-20 year olds and denying them the rights that people 21 and over currently enjoy actually solves anything. 

While some say that allowing only members of the military to drink at 18 in Alaska would violate the Equal Protection Clause (14th Amendment) and thus be tough to defend in court, that would actually work in our favor should someone choose to fight it.  The pro-21 crowd would then be forced to face the fact that the 21 drinking age in general violates the Equal Protection Clause as well (since is arbitrarily higher than the age of majority), paving the way for the drinking age to be lowered to 18 across the board. 

The proposed bill would also represent the first challenge of the 10% federal highway penalty since Louisiana bowed down to the feds in 1996 and reversed their own court decision.  If Alaska loses any of its highway funding, they can retaliate by cutting off (or threatening to cut off) their vast oil supply to the lower 48 states and Hawaii--OUCH!  That should teach the feds to respect the Ninth and Tenth Amendments for once.

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.

New Review of the 21 Drinking Age

Economist Darren Grant (Sam Houston State University) has recently published online a study on the history, merits, and effectiveness (or lack thereof) of the 21 drinking age.  This study is one of a four-part series on drunk driving and related legislation.  Though he is not a member of Twenty-One Debunked, he nonetheless appears to echo much of what we have been saying all along.  Specifically, it exposes several biases in both the policy-making process and the studies used to support the 1984 federal drinking age law.

If his name sounds familiar, it is probably because we already discussed an older study of his on a previous post.  That study critically analyzed the effects of zero-tolerance drink-driving laws.  He also has a working paper that looks at both MLDA and drunk-driving laws in general, in which he found that hard-to-measure "social forces" were generally far more important than any of these laws, and that fact tends to skew the estimated effects of these laws.

One notable aspect of his current study concerns what we like to call "The Incredible Shrinking Effect Size" of the 21 drinking age.  For the studies that were presented at the federal hearings around 1984, and got the most attention, effect sizes of 30% or even higher (in terms of 18-20 year old traffic fatality reductions) were often reported.  However, several other studies found much smaller ones, especially the more recent regression-based ones.  Is it 30%?  Or maybe it's 20%.  Or maybe it's 13%.  Or maybe 11%.  Or maybe 7%.  Or maybe 5%.  Or maybe it's really zero, or even a net increase in deaths.  And yes, there are studies that found the latter.  But politics prevailed over science nonetheless.

One should also realize that NHTSA's estimate on the lives currently saved by the 21 drinking age (25,000 total, or 900 per year) is based on an unpublished in-house study from 1985 using only 13 states.  That study found a reduction of 13%, and NHTSA simply extrapolated that figure to the number of 16-20 year old fatalities in later years.  This number is thus junk, especially since studies like Miron and Tetelbaum (2009) found that the apparent effect wore off after the first year or two, was only found in the early-adopting states, and was offset by increases in fatalities among drivers under 18.  Other studies, like Asch and Levy (1987 and 1990), Males (1986), and Dee and Evans (2001) find that any lives of 18-20 year olds that appear to be "saved" are merely delayed a few years to the 21-24 age group.  Thus there is no net benefit in the long run to keeping the drinking age at 21.

It's time to put science ahead of ideology for once.  What better time than now?

Alaska Considers Lowering Drinking Age for Troops

Alaska, the last frontier, is considering lowering the drinking age to 18--but only for members of the U.S. Military.  While we at Twenty-One Debunked would like to see it lowered to 18 across the board, this would be a great first step in the right direction.  And it deserves a 21-gun salute.

It would also be the first time the 10% federal highway funding penalty would be tested since Louisiana did so in 1996.  While we don't know how Alaska would respond to that, one should remember that, despite their tiny population, they have lots of oil that the lower 48 and Hawaii are dependent on.  Thus, it would probably be foolish for the feds to enforce the FUDAA against such a state and risk retaliation.  Also, the so-called "blood-borders" argument (one of the reasons the FUDAA was enacted) would not really apply due to Alaska's isolation from the rest of the nation.  Not like it was a particularly good argument to begin with, since studies of the purported effect have been inconsistent, and the still-tolerated "blood-borders" of dry/wet counties are far worse since they directly involve a much larger share of the driving population.  Besides, a uniform drinking age of 18 would also eliminate "blood-borders" just the same, and even if varying state drinking ages are tolerated the feds would still have the power to make drunk driving across state lines a federal offense punishable by many years in federal prison.  Thus the "blood-borders" argument is a canard.

Remember, Alaska was one of the first states to lower the drinking age in 1970, even before the 26th Amendment lowered the voting age in 1971.  We wish lots of luck to the Land of the Midnight Sun.

Our Views on the BEER Act

A recent bipartisan bill in Congress known as the BEER Act has making headlines lately.  What it would do is significantly reduce the federal beer excise tax for small domestic brewers (less than 2 million barrels per year) and leave the normal rate untouched, essentially making the beer tax more progressive than it currently is.  While the small brewers currently get a somewhat reduced rate on the first 60,000 barrels, the bill would further reduce this rate as well as the rate on barrels up to 2 million, and only on those brewers who produce a total of 6 million barrels or less.  And this seems to be one of the few things that our increasingly divided Congress can agree upon.

Although we at Twenty-One Debunked have repeatedly called for significantly higher alcohol taxes (beer, wine, and distilled spirits) at both federal and state levels as part of our comprehensive plan to lower the drinking age to 18, we support the BEER Act since it is specific to small brewers (microbrewers).  We would never support a significant tax hike on microbrewers for three reasons:  1) they are far less able to absorb such a tax hike than larger brewers, 2) it would bring in very little revenue in practice relative to tax hikes on larger brewers, and 3) their products are already expensive enough, and are thus far less likely to be abused than their cheaper major brewer counterparts.  These small brewers contribute not just higher product quality, but numerous jobs for Americans that pay a decent wage.  So lets give them a shot in the arm, not a kick in the teeth.

Further Proof of White Noise Syndrome

We have commented in previous posts about a phenomenon we like to call "White Noise Syndrome", or the shifting of deaths from one age group to another when the drinking age is changed.  Sociologist Mike Males refers to this as a "seesaw effect".  This has been documented in several peer-reviewed studies, namely Males (1986), Asch and Levy (1987 and 1990), and most recently in Dee and Evans (2001).  Studies like Carpenter and Dobkin (2010) which find increases in deaths upon turning 21 (today, with a 21 drinking age) seem to dovetail with these results.  Of course, as with anything not every study has agreed with these results, and estimates of net effects varied, but they have been pretty tough to refute. 

Now a new study by economics student Dan Dirscherl (2010) at Notre Dame University further confirms the previous studies mentioned.  His award-winning paper, which uses a fixed-effects, difference-in-differences model on data from 1972-1994 finds that a drinking age of 21 (compared with a lower one) not only shifts deaths from 18-20 year olds to 21-24 year olds, but appears to result in a net increase in fatalities among 18-24 olds.  The effect was driven by males, while females saw no effect either way.  Interestingly, the effect on 18-20 year olds was statistically insignificant, while on 21-24 it was highly significant.  This is the dirty (not to mention deadly) secret of the supposed lifesaving effect of the 21 drinking age that the pro-21 crowd would rather sweep under the rug. 

One potential flaw to this study was that legal drinking ages of 18 and 19 (and even 20 for two states) were lumped together as states with an age limit below 21, compared with states at 21.  This could increase the noise in the data.  However, Miron and Tetelbaum (2009) found no statistically significant difference between drinking ages of 18, 19, or 20 on traffic fatalities in any of their models, even those models that found significant effects for a drinking age of 21 relative to 18.  (Of course, the best model found no lifesaving effects in the long run for MLDA 21 either.)  Another criticism one could make is that Dirscherl did not include data for those under 18.  Again, however, Miron and Tetelbaum found during a robustness check of their own study that a drinking age of 19, 20, or especially 21 increases fatalities of drivers under 18, contrary to what the "trickle-down" or "low-hanging fruit" theory predicts.  Still another criticism is that Dirscherl (like Miron and Tetelbaum) used total traffic fatalities and not "alcohol-related" ones.  But there is no reliable data for "alcohol-related" fatalities before 1982, and even after that the data can be biased due to differences in testing rates.  When using data going that far back, when about 2/3 of teenage fatalites were alcohol related, total fatalities would likely be sufficient, but surrogates like single-vehicle nighttime fatalities are a good robustness check.  And both studies by Asch and Levy do exactly that, with similar results. 

Of course, alcohol-related deaths among young people are by no means limited to the highways.  There is virtually zero evidence that non-traffic alcohol-related fatalities as a whole are significantly reduced by the 21 drinking age, and effects on specific causes of non-traffic death have been inconsistent at best.  In fact, from 1998 to 2005 (years during which enforcement of the 21 drinking age generally increased), these fatalities among 18-24 year olds increased significantly, including a near-tripling of alcohol poisoning deaths for this age group.  It is entirely plausible that forcing alcohol use underground for 18-20 year olds would make it more dangerous than it has to be, most notably for alcohol poisoning deaths (which are really just the tip of the iceberg of high-risk drinking).  An honest cost-benefit analysis of the 21 drinking age should take these deaths into account as well.

We did our own research as well, using the CDC WONDER database to look up any deaths that mentioned "alcohol" in the cause of death for 15-24 year olds.  They group ages by 15-19 and 20-24 instead of 18-20 and 21-24, but the data are still useful for our purposes.  Shown below are the alcohol-related death rates per million people in each of the two age groups.

In other words, raising the drinking age to 21 appears to have been a shell game at best, and those who support it have quite a bit to answer for.  It's a lot like the movie White Noise 2, hence our term for this unfortunate phenomenon.

More Evidence Drinking Age is Irrelevant to "Big Booze"

One common thought-terminating cliche that the pro-21 crowd loves to use to discredit their opponents is to try to link them to Big Booze (i.e. the alcohol industry).  But there is really no hard evidence that Big Booze would respond to changes in the legal drinking age with anything more than a collective shrug. 

A case in point is SAB Miller, the resulting multinational merger of South African Brewery and Miller Brewing Company (who also owns Coors and Molson).  Recently there has been some talk about South Africa considering raising its drinking age from 18 to 21 (which we hope does not happen), yet a recent article dismisses any claims that such a change would affect the company's share prices.  Why?  The quote below says the gist of it:

The general practice found in countries where the age limit for drinking is 21 is that those teenagers in the 18 to 20 years range ask legally-competent people to buy beer for them. This is also expected by commentators to happen in South Africa as well, as it does in many other parts of the world where 21 is the legal drinking age.

Coupled with another quote:  "Teenagers are not necessarily a huge part of SAB's business in the first place".  Not even in a nation like South Africa where the drinking age is 18 and very poorly enforced.

And there you have it.  No significant effect on the alcohol industry as a whole.  But what about the restaurant/bar industry?  Surely they would be affected, right, since it would shift drinking away from bars and toward underground parties?  In 1984, the National Restaurant Association understandably came out against the national raising of the drinking age in the United States.  However, they have since backed down once it was a done deal, implying that they had far bigger fish to fry.  And the alcohol industry overall has been relatively silent on the issue both then and now.

While neither the alcohol nor the hospitality industries are making any serious effort to reduce America's drinking age, they have both* been (and still are) fighting tooth-and-nail every attempt to raise alcohol taxes, restrict advertising, lower blood alcohol limits for DUI, increase sobriety checkpoints, and install ignition interlocks for convicted drunk drivers.  All while the groups like the distiller-funded Century Council ostensibly dedicate themselves to fighting underage drinking (while supporting the 21 drinking age), supporting tough penalties for underage drinkers and social hosts, and even "reverse-stings" to bust underage purchasers (as opposed to those who profit from such consumption).  Now that really says something about the effectiveness of the 21 drinking age versus these other countermeasures they hate in reducing heavy and problem alcohol consumption (which constitutes the majority of Big Booze's revenue) among all ages.  But groups like MADD are so gung-ho about the sacred cow that is the 21 drinking age that they fail to see this obvious fact about how their foes operate.

So where do we, Twenty-One Debunked, stand on the countermeasures the industry opposes?  We support them, for the most part.  We believe that the alcohol taxes should be raised significantly, for all beverages (except microbrews), with the tax proportional to alcohol content.  We believe that alcohol advertising should not be allowed to target minors, and should be restricted to the greatest extent allowed under the U.S. Constitution, similar to tobacco.  We support reduced blood alcohol limits for driving, with graduated penalties that steeply increase with BAC level, and the penalties for the highest levels should be much higher than they are now.  We believe that first offenders should, at a minimum, be required to have ignition interlocks if (not when) they get their licenses back, revocations of which should be permanent upon the second offense.  These folks are ticking time bombs that will kill someone if left unchecked.  And while we have nothing in principle against checkpoints that are conducted properly, we believe that roving patrols are more effective and cost-effective in catching drunk drivers and saving lives. 

As for the drinking age, if our wish is granted and it is ever reduced to 18, we would support tough enforcement targeting vendors above anyone else, and only very modest civil penalties (if any) against underage drinkers themselves.  Until that day comes, we believe that liquor law violations involving 18-20 year olds (and no one under 18) should be made the lowest law enforcement priority and penalites dramatically reduced if not eliminated.  The drinking age should also never be used as an excuse to violate the Constitution.  Social host laws, at least for those over 18, should be repealed.  And no one of any age should be jailed or receive a lifelong criminal record solely for drinking alcohol in a manner that does not harm others, as the punishment does not fit the "crime".

It should also go without saying that Twenty-One Debunked does not, and will never, accept even a single dime from Big Booze or the hospitality industry.  No offense to them, but our integrity is worth much more than anything they could ever possibly offer.

*One such industry trade group is the American Beverage Institute, of which MADD's turncoat founder Candy Lightner is currently a member (or at least was back in the 1990s) despite still supporting the 21 drinking age as of 2008.  Also, take a look at some of the supporters of one of the federal government's most prominent pro-21 websites.

Latest Age of Onset Study Is Less than Meets the Eye

Just in time for St. Patrick's Day, a well-known drinking holiday, a new study comes out about the controversial relationship between age of onset of drinking and later alcohol dependence.

What the study apparently found was that 1) those who began drinking at all before the age of 11 (!) were statistically more likely to develop alcohol dependence than those who began later, and 2) those who began drinking regularly before age 21 were statistically more likely to develop alcohol dependence (but not alcohol misuse) than those who began later, with interestingly no statistically significant difference between those who began in early adolescence (11-14), middle adolescence (15-17), and those who began between 18-20 years of age. 

However, there is less here than meets the eye.  First of all, for regular drinking (defined as 2 or more drinks per week, an arbitrary distinction and not a real lot) they lumped together those who drank lightly or moderately with those who drank heavily, and lumped together those who started at exactly 21 with those who started much later.  Well DUH--those who had any interest at all in alcohol would likely have begun drinking at least occasionally before 21, and those who would actually wait that long tend to be nondrinkers for the most part. People uninterested in alcohol are unlikely to become alcoholics, plain and simple.  This is especially true since those individuals who began drinking regularly after 21 but did not initiate any drinking before 21 were excluded from the study.  Also since the study only followed participants to age 33, those who began drinking after 21 may not have had enough time for problem drinking to show up in the study.  As for those who began drinking regularly between 18-20, it is likely that most of them had their first drink well before 18 since most of that study's participants began drinking very early, but this distinction was not made among the reportedly regular drinkers.  And those who had their first drink at 18-20 were found to be 65% less likely to become alcoholics than those who began before the age of 14, making it rather curious why the researchers did not adjust for this in the analyses of regular drinking.

Other flaws existed as well.  The study did not adequately control for general deviant tendencies, and deviant people are more likely to break the law (such as the MLDA), more likely to begin drinking much earlier (or later) than their peers, and more likely to become alcoholics.  The only control variables were race/ethnicity, gender, poverty, tobacco, and illicit drug use, despite the fact that many other variables (e.g. genetics, childhood trauma, peer group, IQ, etc.) may very well have had an effect.  Also, the sample size was fairly small and was likely not representative of the general population, since all participants were initially recruited from schools in high-crime areas of Seattle.  Reporting bias, especially on the question of regular drinking, may also be an issue. Another issue was the apparently non-monotonic relationship between age of onset of regular drinking and alcoholism (starting at age 18-20 had a slightly higher odds ratio than at age 14 and under, though statisically insignificant), which is rather suspicious and runs counter to the idea that the relationship is primarily due to differences in brain development.  Finally, the adjusted odds ratios were 1.6-1.8, and all honest epidemiologists know that odds ratios below 2.0 should be taken with at least a grain of salt, if not a whole pound.

To really control for as many confounders as possible, twin studies are the best choice since their genetics and environment are about as similar as one can get.  A recent twin study (Agrawal et al. 2009) with a larger sample size in Australia found that, while drinking before age 15 was associated with a significantly greater incidence of alcohol dependence, the effect of age of onset diminishes after that point and practically disappears from age 18 onwards. Those who began drinking at 18 were not significantly more likely to become alcoholics than if they had started at 19, 20, 21, or even 23+. Funny how the effect of age on later alcoholism levels off precisely at the country's legal drinking age, 18.  And in a country that has roughly the same rate of alcoholism that we do despite their lower drinking age.

To prove causation as per the Bradford-Hills criteria, one crucial criterion is "biological plausibility."  While that is not exactly the same thing as "truth", without it one cannot have a great deal of confidence that a relationship is truly causal.  Animal studies are often used for this purpose, but rodents are hardly ideal to test a hypothesis like this since their adolescence occurs far too quickly to distinguish between specific ages, not to mention the obvious fact that rats are not people.  Thus, such studies have been rather inconsistent.  Nonhuman primates, such as monkeys, are better suited to such a task.  And the only known monkey study of whether earlier-onset drinkers are more likely to get hooked than later-onset ones shows no connection with age of onset per se, even though the monkeys were dosed with "binge" amounts.  This suggests that genetic, social, and cultural factors are most likely far more important than age of onset for humans, if the latter is even causal at all, and that the difference between an age of onset at 18 vs. 21 is practically negligible.

Also, one ought to take a look at a previous post about our neighbor to the north.  Again, they also have a roughly equivalent alcoholism rate as the USA, despite Canada's lower drinking age as well as their demographic and geographic features more conducive to heavy drinking.  Besides, it's not like the 21 drinking age really stops 18-20 year olds from drinking--even the latest study showed that nearly 9 out of 10 people will do so before age 21, many of them having initated at or before age 15.  Thus, it is unrealistic to expect everyone to not drink a drop until 21 or later, and far better to teach moderation and responsible drinking.  Yes, there were a few people who waited until 21 or later before drinking, but that was also true in the Australian study, in a country whose drinking age has been 18 for decades (and over a century in some parts).  It's time for Americans to stick their heads out of their current anatomically-impossible positions and join the rest of the civilized world.