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Key Results: Minimum Legal Drinking Age Policy
Citations Listed in Key Results
- There is ample evidence in support of the effectiveness of MLDA-21.
When the age-21 restriction was initiated across states, driver alcohol involvement in fatal traffic crashes declined more significantly among the 18- to 20-year-old population than among drivers aged 21 and older. In 1982, the first year for which alcohol estimates were available in NHTSAs Fatality Analysis Reporting System (FARS), 48% of drivers aged 18 to 20 involved in fatal crashes had some alcohol, compared to 40% for drivers aged 21 and older. In 1989, the year after the last states had enacted their MLDA-21 laws, 34% of drivers aged 18 to 20 involved in fatal crashes had some alcohol, compared to 32% for drivers aged 21 and older. From 1982 to 1989, 18- to 20-year-old drinking drivers in fatal crashes declined 14 percentage points, while drivers aged 21 and older declined by 8 percentage points. In 2006, 26% of the drivers involved in fatal crashes in each age group had some alcohol (NCSA, 2005).
Numerous studies since the National Uniform Drinking Age Act have confirmed associations between raising the MLDA to 21 and reductions in underage alcohol consumption, youthful traffic fatalities, and other harm (e.g., Arnold, 1985; Dang, 2008; Decker, Graitcer, & Schaffner, 1988; O'Malley & Wagenaar, 1991; Ponicki, Gruenewald, & LaScala, 2007; Shults et al., 2001; Toomey et al., 1996; Voas et al., 2003; Wagenaar & Toomey, 2002; Williams et al., 1983; Womble, 1989). Research has revealed a decrease in six types of fatal injuries (including deaths related to car crashes, suicides, homicides, falls, drowning, and alcohol poisoning) for 15- to 24-year-olds following implementation of the MLDA-21 law (NRC/IOM, 2004). NHTSA credits state laws raising the legal drinking age to 21 with preventing approximately 900 traffic deaths annually (NCSA, 2005).
A recent study indicated that the laws making it illegal for youth to possess or purchase alcohol if they are younger than age 21 have reduced the rate of underage drinking drivers in fatal crashes by 11% (Fell et al., 2008). That analysis controlled or accounted for numerous other factors - other drunk driving laws, alcohol consumption, the economy, the culture of the state, and vehicle miles driven in the state - that could have affected underage drinking and driving. Even with all those factors accounted for, the core laws raising the minimum drinking age to 21 still resulted in a substantial reduction in youth traffic fatalities. This confirms the findings of prior research but has a stronger design than many earlier studies.
NHTSA estimates that minimum drinking age laws have prevented 26,333 traffic deaths since 1975. This estimate represents people of all ages who otherwise would have been involved in a fatal crash involving 18- to 20-year-old alcohol-impaired drivers (Figure 1). This number would be higher if the number of lives saved through the prevention of other underage drinking deaths (e.g. suicides, homicides, unintentional injury deaths) were included.
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- Zero-tolerance laws reduce fatal traffic crashes for youth aged 20 and younger.
As of June 1998, all states and the District of Columbia have set a BAC limit of .02 or lower for drivers younger than aged 21 (zero-tolerance law) (Voas et al., 2003). This law has also been associated with significant reductions in the involvement of drinking drivers aged 20 and younger in fatal traffic crashes (Hingson, Heeren, & Winter, 1994; Voas et al., 2003; Wagenaar, O'Malley, & LaFond, 2001). These laws could be made more effective via corresponding media campaigns publicizing them (Blomberg, 1992).
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- More states need license sanctions for false identification laws because they are effective.
Fake identification laws in the states that have criminal or administrative license suspension sanctions account for about a 7% decrease in underage drinking drivers in fatal crashes (Fell et al., 2008). States should therefore ensure that these license sanctions are in their laws if they expect it to have an effect on drinking and driving among youths. All 50 states and the District of Columbia have fake identification laws, but only 6 states have administrative license suspension penalties associated with their laws. Eight states do not have any driver's license sanction in their fake identification law.
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- Reductions in homicides and suicides are also associated with MLDA-21 laws.
A review of studies on the effects of minimum age drinking laws on alcohol consumption found that, as the legal age was lowered, drinking increased. Conversely, raising the legal drinking age reduced the consumption of alcohol (O'Malley & Wagenaar, 1991). Studies show MLDA-21 laws are associated with reductions in homicides (Jones et al., 1992), suicides (Birckmayer & Hemenway, 1999; Jones et al., 1992), and unintentional injuries (Jones et al., 1992) by 18- to 20-year-olds. Alcohol use interacts with conditions such as depression and stress that contribute to suicide, the third leading cause of death among people aged 14 to 25 (Anderson, 2001; Garlow, 2002). In one study, 37% of eighth grade females who drank heavily reported attempting suicide, compared with 11% who did not drink (Windle, Miller-Tutzauer, & Domenico, 1992). Individuals younger than 21 commit 45% of rapes, 44% of robberies, and 37% of other assaults (Levy, Miller, & Cox, 1999), and it is estimated that 50% of violent crime involving all ages is alcohol-related (Harwood, Fountain, & Livermore, 1998). Researchers have found that as the legal drinking age was lowered, the number of social problems increased, but as the legal age was raised, the number of problems decreased (Hedlund et al., 2001; O'Malley & Wagenaar, 1991).
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- Merely comparing minimum legal drinking age (at 21) with other age-related rights (military recruitment and voting rights) and behaviors does not take into account other factors.
Many rights have different ages of initiation. In most states in America, a person can obtain a hunting license at age 12 and drive at age 16. U.S. citizens can vote and serve in the military at 18. Other rights that are regulated include the sale and use of tobacco and the age of legal consent for sexual intercourse and marriage. Vendors, such as car rental facilities and hotels, also have set the minimum age for a person to use their services - 25 years old to rent a car and 21 years old to rent a hotel room. The minimum age for initiation is based on the specific behaviors involved and takes into account the dangers and benefits of that behavior at a given age (Fell, 1986; Wagenaar & Toomey, 2002). The minimum age for initiation for certain rights is also based on physical development, including brain function. The military recruits 18-year-olds fresh out of high school because they are physically fit and highly trainable. This does not mean these 18-year-olds are ready for alcohol use, nor would alcohol improve their military performance.
Alcohol affects teens differently than adults. A teenager may look like an adult physically and may even appear more physically fit, but the teenager's body is still developing. It actually takes less alcohol for a teenager to be intoxicated than it does for an adult in his or her twenties (Zeigler et al., 2004). A normal adults liver can safely process an estimated 50 alcohol calories an hour (one ounce of 40% alcohol). However, studies show that a teenager's liver can only process half that amount. To ingest only 25 alcohol calories per hour, a teenager could drink no more than one-fourth of a "light" beer in one hour (Zeigler et al., 2004). Although adolescence is often characterized by increased independence and a desire for knowledge and exploration, it is also a time when brain changes can result in high-risk behaviors, addiction vulnerability, and mental illness, as different parts of the brain mature at different rates.
There is mounting evidence that repeated exposure to alcohol during adolescence leads to long-lasting deficits in cognitive abilities, including learning and memory in humans. In one study of subjects recruited from treatment programs (aged 13 to 19), it was observed that teens who returned to drinking after the treatment program suffered further declines in cognitive abilities, particularly in tests of attention, over the next 4 years (Tapert & Brown, 1999).
Early onset of drinking by youth has also been shown to significantly increase the risk of future alcohol-related problems (e.g., alcohol dependence as well as getting into fights, experiencing traffic crashes, and other unintentional injuries after drinking), controlling for a variety of personal demographic characteristics as well as history of smoking and drug use and family history of alcoholism (Grant & Dawson, 1997; Hingson et al., 2000; Hingson, Heeren, & Zakocs, 2001; Hingson et al., 2002; Hingson, Heeren, & Winter, 2006). Further, early drinking onset has been linked to suicide attempts (Swahn & Bossarte, 2007; Swahn, Bossarte, & Sullivent, 2008). In addition, the consequences appear to be more severe for those who start drinking at a younger age. In 2004, a joint review for the National Research Council and Institute of Medicine (Hingson & Kenkel, 2004) revealed that youth who started drinking before age 15, compared to those who waited until they were 21, were 12 times more likely to be unintentionally injured while under the influence of alcohol, 7 times more likely to be in a motor-vehicle crash after drinking, and 10 times more likely to be in a physical fight after drinking (Grant & Dawson, 1997; Hingson et al., 2000; Hingson et al., 2001; Hingson et al., 2002, NRC/IOM, 2004). After analytically controlling for history of alcohol dependence, frequency of heavy drinking, years of drinking, age, gender, race/ethnicity, history of cigarette smoking, and illicit drug use, those who started drinking at age 18 were nearly twice as likely to be unintentionally injured, be in motor-vehicle crashes, and be in physical fights while under the influence of alcohol compared to those who started at age 21.
Youth who start drinking at age 18 have twice the odds of drinking to intoxication than youth who start at age 21 (Hingson et al., 2000). Youth who start drinking at age 18 have a 33% to 52% greater chance of being injured while under the influence of alcohol in their lifetime compared to youth who start drinking at age 21 (Hingson et al., 2000). Fifteen percent of youth who start drinking at age 18 become alcohol dependent at some point in their lives compared to only 9% of youth who wait until age 21 before drinking (Hingson et al., 2006). Youth who started drinking at age 18 have a 2.4-fold increase in risk of being involved in a motor-vehicle crash because of drinking too much in the past year compared to youth who started drinking at age 21 (Hingson et al., 2002). Youth who started drinking at age 18 have a 50% to 60% greater chance of being in a physical fight while drinking or after drinking in the past year compared to youth who started drinking at age 21 (Hingson et al., 2001).
Research shows that when the drinking age is 21, those younger than 21 drink less and continue to drink less through their early twenties. The lower rates of drinking before age 21 are not compensated for by a higher rate of drinking after reaching 21 (O'Malley & Wagenaar, 1991), as some have conjectured. In fact, research shows that the opposite is true (Wagenaar, 1993). Early legal access (at age 18) is associated with higher rates of drinking later in life. According to the National Institute on Alcohol Abuse and Alcoholisms (NIAAA's) Initiative on Underage Drinking, 40% of those who started drinking before the age of 15 met criteria for alcohol dependence at some point in their lives (NIAAA, 2006). This is four times greater than those who begin drinking at age 21. Twenty-eight percent who start drinking at age 17 and 15% who start drinking at age 18 developed alcohol dependence. Youth who start drinking at age 18 are 1.4 times more likely to become alcohol dependent than those who start at age 21 or older, even after controlling for age, gender, race/ethnicity, education, marital status, family history of alcoholism, childhood depression, antisocial behavior, and history of smoking and drug use. No evidence exists to indicate that young people will learn to drink responsibly simply because they can consume alcohol legally at a younger age (Hingson et al., 2002 Wagenaar, 1983a). Countries with lower drinking ages suffer from alcohol-related problems similar to or greater than those in the United States (Grube, 2005; Rehm et al., 2001; Room, 2003).
Lowering the drinking age, as was done in the 1970s in America, has recently been shown to significantly increase alcohol-related traffic injuries for the age groups affected in New Zealand (Kypri et al., 2006). Lowering the drinking age from 21 to 18 will also expose more youth to excessive alcohol consumption that can lead to problems with brain function (Brown et al., 2000; Tapert & Brown, 1999). Ongoing research indicates the brain is not fully developed in many humans until about age 25 (Giedd, 2004; Spear, 2002; Sowell et al., 1999).
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- Lower drinking ages in Europe do not support lowering the minimum legal drinking age in the United States.
European countries are held up as examples of where more liberal drinking age laws and attitudes may foster more responsible drinking by young people. It is often asserted that alcohol is more integrated into European (especially southern European) culture and that young people there learn to drink at earlier ages within the context of the family. Consequently, young Europeans learn to drink more responsibly than do young Americans. This may be so in a handful of countries, but in reality, a greater percentage of 15-year-olds in most European countries reported being intoxicated in the past 30 days than in the United States (see Figure 2; Grube, 2005; Hibell et al., 2004; Johnston et al. 2004). Evidence also indicates that some European youth have higher rates of alcohol-related problems because of their heavy drinking (Rehm et al., 2001; Room, 2003).
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- Binge drinking by youth declined after drinking ages were raised to age 21 nationwide and has been stable at levels lower than in the early 1980s. There is no evidence that the MLDA-21 law is associated with any increase in binge drinking.
Binge drinking (i.e., reaching a BAC =.08; typically having five or more drinks for males and four or more for females at a drinking session) is a major problem at many colleges (Hingson et al., 2005; Johnston et al., 2007). Binge drinking among college students has been fairly steady for the past 10 years. Between 1997 and 2006, the proportion of college students reporting binge drinking from the Monitoring the Future (MTF) survey ranged from a high of 41.7% in 2004 to a low of 38.5% in 2003. The percentage of college students who reported being drunk in the past 30 days shows similar fluctuations and results between 1991 and 2006, with several ups and downs during that period (see Figure 3). Overall, the proportion of 19- to 20-year-olds (college and no college) reporting binge drinking from the MTF survey has fluctuated from a low of 31.7% in 1995 to a high of 37.0% in 1991 (see Figure 4). The proportion of 12th graders reporting binge drinking in the last 2 weeks from the MTF survey actually declined recently, ranging from 29.8% in 1991 to a high of 31.5% in 1998 to a low of 25.9% in 2007 (Johnston et al., 2008).
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- There are current strategies that show evidence of reducing underage drinking.
There is evidence that communities that combine public information, training for servers, and enforcement of MLDA-21 laws can have an effect on underage drinking by reducing alcohol availability. An evaluation of a multi-community program entitled Complying with the Minimum Drinking Age (CMDA) demonstrated significant reductions in sales rates to youth due to enforcement checks (Wagenaar, Toomey, & Erickson, 2005). Communities Mobilizing for Change on Alcohol (CMCA) have shown evidence of the effectiveness of enforcement programs and efforts in reducing the consequences of underage drinking (Wagenaar et al., 1994; Wagenaar, Murray, & Toomey, 2000). A Community Prevention Trial to Reduce Alcohol-Involved Trauma that combined community mobilization, media advocacy, responsible beverage service training, and enforcement showed evidence of reducing sales to underage, underage drinking and driving, and underage injuries (Holder et al., 1997).
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