relate most directly to the public health and to the other fields of investigation explored in previous chapters.
An integrated perspective that encompasses interventions aimed at both supply and demand can yield important advances by overcoming disciplinary and bureaucratic boundaries. Many aspects of drug control and its enforcement are inescapably related to mainstream fields of drug abuse research, especially etiology, prevention, and treatment. Because the law and its enforcement affect the price and accessibility of illicit drugs, drug control policies can affect many aspects of drug-using behavior, including which drugs are used and how they are ingested. A full understanding of factors relating to initiation or intensification of drug use might usefully encompass measures of perceived availability and the perceived likelihood that sanctions (both legal and social) will be imposed. Treatment outcome studies might take into account the impact of variations in drug availability on entry and retention, as well as the coercive "leverage" produced by the threat of prosecution or punishment. The design of community prevention programs might encompass measures of drug availability (e.g., price and access) as well as other variables relating to the intensity of law enforcement in the communities being studied. As noted in Chapter 7, the consequences of drug abuse (e.g., violence) are often intertwined with the sequelae of illicit drug markets and drug law enforcement.
An important trend in public health research is the inclusion of legal controls and interventions within a single model of drug abuse research. A prime example is injury control. For example, the field of highway safety encompasses studies of the effects of mandatory seatbelt laws, mandatory helmet laws, speed limits, and various types of licensing restrictions. In recent years, injury control researchers have also focused on the effects of gun controls on firearms injuries. The compelling need to bring legal controls within a comprehensive public health research model has recently been recognized in the field of tobacco research, where studies are being conducted on the design and enforcement of youth access restrictions, the effects of advertising restrictions, and the effects of a significant increase in tobacco excise taxes (IOM, 1994). In fact, some public health officials and tobacco research funding agencies have come to believe that "policy research" is an essential component of a tobacco research program (Davis, 1995).
Arguments about drug control policy proceed too often on the basis of intuition and supposition rather than empirical data. Even though some of the disputed issues defy scientific investigation, many of the controver-