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The Effects of Alcohol Access on Consumption and Mortality. Christopher (Kitt) Carpenter and Carlos Dobkin. We thank NIH/NIAAA for financial support R01-AA017302-01. Comments welcome. Overview. Research Question: What is the causal effect of alcohol consumption on mortality?
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The Effects of Alcohol Access on Consumption and Mortality Christopher (Kitt) Carpenter and Carlos Dobkin We thank NIH/NIAAA for financial support R01-AA017302-01. Comments welcome.
Overview • Research Question: What is the causal effect of alcohol consumption on mortality? • Regression Discontinuity (RD) design that leverages the minimum legal drinking age (MLDA). • We find that the MLDA substantially reduces both alcohol consumption and many types of mortality.
Outline of Talk • Motivation & Literature Review • Research Design & Data Description • Results on Alcohol Consumption • Results on Mortality • Discussion
Motivation • Underage drinking “costs” society $53 billion annually (IOM 2004) • Far more prevalent than tobacco/drug use • Well established link with traffic crashes • Less evidence on other types of mortality • Governments devote lots of resources to reducing youth drinking & adverse effects • Most direct regulation: MLDA • Particularly relevant now
Why are youths of special interest? • The age-profile of drinking and nearly all adverse outcomes (acute mortality, crime, risky sex) peaks at late teens/early 20s • Age-targeted policies can generate meaningful effects on overall outcomes
Relevant Literature • MLDA & drinking: panel evaluations • Dee 1999, Cook & Moore 2001, others • Youths exposed to lower MLDA drink more • MLDA & mortality: panel evaluations • Lots of evidence on traffic fatalities (Dee 1999) • No consensus on other causes (suicide, injuries, homicides, etc.)
Limitations of MLDA Literature • Exposure to a lower MLDA is not random • Reflects policy preferences, unobserved sentiment toward drinking, etc. • MLDA effects on drinking typically small (e.g. 4-10 percent) • Not all studies find effects (e.g. Kaestner 2000)
Our Contributions • We have a transparent and robust research design much less vulnerable to OVB • Most comprehensive examination of mortality • Much more precise estimates (more data & refined age variable) • We combine our consumption and mortality estimates to obtain the implied IV estimate
Research Design • Focus on discrete change in access to alcohol at age 21 due to MLDA law • Regression Discontinuity Design • Parametric: Model age profile with polynomial • Nonparametric: Local linear regression • Evaluate research design • Check fit of models graphically • Check continuity of potential confounders
Regression Discontinuity Design • Parametric • Polynomial in age fully interacted with a dummy for over age 21 (Ov21) • Local Linear Regression • Follow Fan & Gijbels (1996) and estimate the rule of thumb bandwidth • Triangular Kernel
Data: Alcohol Consumption • 1997-2005 National Health Interview Survey (Sample Adult Supplement) • 16,107 Adults 19-22 Years of Age • Date of birth and date of interview • Questions about lifetime drinking, past year drinking participation, heavy drinking
Summary of Alcohol Findings • There is an immediate persistent increase in alcohol consumption at age 21 • Only modest evidence of an increase in first time use of alcohol • More people are drinking but drinking intensity does not appear to have gone up much
Data: Mortality • 1997-2004 Vital Statistics Mortality • Exact date of birth and date of death • Census of Deaths in the United States • Considerable Detail on Cause of Death • We include dummies for large “birthday effects”
Summary of Mortality Findings • Large, persistent increase in mortality • Increase due largely to MVA but also evidence of an increase in suicides • Implied IV: 10 percent increase in drinking days increases mortality by 4.3 percent
Conclusions • Minimum Legal Drinking Age (MLDA) laws substantially reduce drinking and mortality • The age profiles of consumption suggest it is not people’s first experience with drinking • Main route is exposure (e.g. drinking days) • Implied elasticities suggest a substantial amount of mortality among youths is due to drinking