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A Natural Experiment to Test the Effect of Sanction Certainty and Celerity on Substance-Impaired Driving: North Dakota's 24/7 Sobriety Program

NCJ Number
Journal of Quantitative Criminology Dated: 2020
Date Published

This study evaluated the deterrent effect of a program for arrestees charged with substance-impaired driving that increases the certainty and celerity of sanction for arrestees ordered to abstain from alcohol and other drugs. 


The evaluation examined participant compliance with orders to abstain from alcohol and other drug use via breathalyzer, body-worn continuous alcohol monitoring devices, transdermal drug patches, and urinalyses. It then assessed the impact of the 24/7 Sobriety program on substance-impaired driving arrests. Using variation across counties in the timing of program implementation in North Dakota as a natural experiment, the evaluation used difference-in-differences fixed effects Poisson regressions to measure the program’s effect on county-level arrests for substance-impaired driving. Just over half of participants ordered to abstain from substance use completed 24/7 Sobriety without a detected substance-use event. At the county level, the program was associated with a 9-percent reduction in substance-impaired driving arrests after accounting for the impact of oil exploration in the Bakken region, law enforcement intensity, alcohol availability, whether the state’s large universities were in session, and socio-demographic characteristics. The study found that the Bakken oil boom was associated with a 22-percent increase in substance-impaired driving arrests. The evaluation’s findings suggest that frequent monitoring combined with increased sanction celerity deters crimes that involve substance use. Although these results are generally consistent with an earlier study of 24/7 Sobriety in another state, differences in the study outcome measures implementation choices across states make direct comparisons difficult. More can be learned by conducting randomized controlled trials that vary time on program, testing technology, and/or level of sanction. (publisher abstract modified)

Date Published: January 1, 2020