A growing body of policy impact studies points to the effectiveness of various local ordinances in either reducing substance use and abuse directly, or reducing the direct and indirect costs associated with their use (U.S. Department of Health and Human Resources [USDHHS]), 1991; Stewart, 1997; Substance Abuse and Mental Health Services Administration, 1998). Using government policy to regulate tobacco and alcohol accessibility to youth, as well as regulating the circumstances under which these drugs are used tin communities, can be effective in reducing youth substance use for several reasons. Goverment policies that regulate the availability and use of tobacco and alcohol can impact all members of a community, both those who use substances and those who may be affected by users. Policies can reduce the use of tobacco and alcohol through restrictions on purchase age, hours of sale, and locations and circumstances in which substances may be sold or used. Restricting general availability not only influences current consumers, but also reduces the availability of tobacco and alcohol for youth who might be tempted to begin use.