Drunk Driving in the United States: An Examination of Informal and Formal Factors to Explain Variation in DUI Enforcement across U.S. Counties

Abstract: This research aims to understand how informal non-legal factors, such as normative climates, and formal legal factors, such as open-container laws, seat-belt laws, and police force strength are related to variation in drunk driving (DUI) enforcement across U.S. counties. In particular, this study focuses on explaining whether differences in the macro-level normative climates toward drinking (i.e., anti-drinking normative climates and pro-drinking normative climates) are related to levels of DUI enforcement by police. It is unclear whether informal factors exert effects on DUI enforcement, independent of formal legal factors. This study takes a population-based approach and uses cross-sectional information (1999-2001) compiled from a variety of official agencies that disseminate county-level data. Results from Exploratory Spatial Data Analysis (ESDA) and Spatial Regression Analyses suggest that areas with anti-drinking normative climates are associated with higher levels of DUI enforcement. Conversely, areas with pro-drinking normative climates tend to be associated with lower levels of DUI enforcement. Overall, these findings suggest that normative climates toward drinking account for some of the variation in rates of DUI enforcement, independent of formal legal factors. Limitations and implications for DUI control and future research are discussed. Keywords: arrest rates, counties, drunk driving, DUI, normative climates INTRODUCTION Effective control of drunk driving (DUI) is a priority of interest groups, public health officials, policy makers, and law enforcement agencies in the United States. Efforts to control DUI generally rely on a deterrence model-that lower rates of DUI are associated with increased formal sanctions and increased certainty of arrest (Jacobs 1989; Ross 1992). However, macro-level informal factors, which are not part of the formal legal system, may also be related to levels of DUI enforcement in an area. Drunk driving varies considerably across the United States, but the factors that account for differences in DUI enforcement by police remain unclear. While a large body of empirical research has examined how formal legal factors, such as DUI laws, are related to variation in DUI behavior (e.g., DeJong and Hingson 1998), much less research has focused on understanding how informal norms may account for variation in DUI enforcement across geographical areas. Informal social norms are fundamental to social organization and human behavior; norms provide informal rules about how people "ought" to behave (Homans 1961). The informal rules, values, and beliefs regarding alcohol consumption are different among groups and across areas of the U.S. In some areas, drinking alcohol is acceptable and normative behavior, whereas in other areas, there is a strong normative climate that severely regulates acceptable drinking. While it is well established that community political and social climates influence police practice (Wilson 1968) and departmental contexts shape police behavior (Mastrofski, Ritti, and Hoffmaster 1987), it is unclear whether police enforcement of DUI varies in relation to macro-level normative climates toward drinking. In contrast to informal factors, the formal legal system features a number of laws, policies, ordinances, and police practices to control drunk driving. However, these laws are not applied equally across areas of the U.S. and they are not equally enforced. For example, several states have laws permitting roadside sobriety checkpoints, but even though checkpoints are legal, there is within-state variation in the frequency in which they are conducted by police. Although DUI-control laws in some areas are associated with lower rates of drunk driving, the extent to which area-wide informal norms exerts effects independent of formal laws has not been established in previous research. The overarching goal of this research is to explain differences in drunk driving across areas and to understand why some places experience higher levels of DUI enforcement than others. …