Alcohol imposes significant social costs on the residents of Montana. The state has one of the highest alcohol-related traffic fatality rates in the nation, and alcohol accounts for more than one-eighth of deaths among working aged adults statewide. 24/7 Sobriety requires alcohol-involved offenders to abstain from alcohol and submit to frequent alcohol testing; those failing or missing a test face an immediate, but brief, jail term. The State of Montana began piloting 24/7 among driving-under-the-influence (DUI) arrestees in Lewis and Clark County in early-2010 and expanded to 22 counties with the passage of House Bill 106 in May 2011. The program also grew to include other alcohol-involved offenses, though DUI arrestees account for more than 75% of program participants. In Montana, 24/7 participants are monitored for an average of 160 days, with a median time of 104 days. Using data from everyone who was convicted of their second DUI charge (DUI-2) from January 2008 to August 2014, this analysis examines the effect of 24/7 participation on the probability of DUI re-arrest for participants within twelve months of their second (DUI-2) arrest date. Results from bivariate probit models which instrument with 24/7 availability to account for potential selection issues provide suggestive evidence that 24/7 participation reduced the probability of DUI re-arrest in Montana (perhaps on the order of 45% to 70% when considering both our main results and sensitivity analysis findings), but missing criminal history information for approximately half of the sample precludes us from making stronger inferences about causality.
Midgette, Gregory and Beau Kilmer, The Effect of Montana's 24/7 Sobriety Program on DUI Re-arrest: Insights from a Natural Experiment with Limited Administrative Data. Santa Monica, CA: RAND Corporation, 2015. https://www.rand.org/pubs/working_papers/WR1083.html.
Midgette, Gregory and Beau Kilmer, The Effect of Montana's 24/7 Sobriety Program on DUI Re-arrest: Insights from a Natural Experiment with Limited Administrative Data, RAND Corporation, WR-1083-MHP, 2015. As of December 7, 2023: https://www.rand.org/pubs/working_papers/WR1083.html