holics are more likely than children of nonalcoholics to start drinking during adolescence [NIAAA, 1997].)

Some of the strongest evidence of the causal role of alcohol in negative outcomes is derived from studies designed to assess the effects of policy interventions targeted on underage alcohol consumption. It is clear from these studies that reducing alcohol consumption among young people reduces such immediate outcomes as deaths, crime, and other consequences of impaired behavior. For example, research has shown that policies that affect alcohol availability, including excise tax rates and the minimum drinking age, have measurable effects on such outcomes as crime, highway fatalities, tobacco and drug use, and sexually transmitted diseases with greater availability associated with increases in these outcomes (Chaloupka, 2004; Chesson et al., 1997; Coate and Grossman, 1988; Cook, 1981; Cook and Moore, 1993a, 1993b; Cook and Tauchen, 1982, 1984; Kenkel, 2000; Ohsfeldt and Morrisey, 1997; Pacula, 1998; Ruhm, 1996; Saffer and Grossman, 1987; Wagenaar and Toomey, 2002). Given that the only plausible mechanisms by which such policies could affect these outcomes are through their effects on the volume and patterns of alcohol consumption, it is logical to conclude that alcohol consumption is indeed a causal agent for these outcomes.

In the case of long-term negative outcomes, the key question is whether reducing underage drinking would also reduce those outcomes. To the extent that individual vulnerability plays a large role, merely delaying the onset of drinking would not necessarily have much of an effect; the vulnerable people would eventually end up as problematic drinkers regardless of when they started. Moreover, many underage individuals who start heavy drinking in their late teens give it up as they reach their late 20s and 30s. The committee has carefully considered the evidence on this important issue—the extent to which early drinking causes later drinking problems, reduces them, or has no effect at all. Clearly predisposition and early alcohol use interact, and the effect of alcohol varies according to the degree of vulnerability of different individuals. However, notwithstanding the complexity of the inquiry, the committee concludes that the evidence establishes a prima facie case regarding the negative effects of early drinking on long-term welfare.

We think that prudent parents and a prudent society should assume, based on the current evidence, that underage drinking increases the risk of future drinking problems and contributes independently to the many deficits experienced by early drinkers over the course of their lives. However, additional research to further refine understanding of the interaction of the multiple interrelated factors on long-term outcomes is warranted.