Drunk driving is a huge public health issue. Ignition interlock devices can reduce DUI recidivism after a DUI conviction. But there is little evidence on how interlock devices might deter first-time DUI offenders. We use a conjoint analysis to measure the deterrence potential of an ignition interlock device as DUI penalty, and find the potential is large: on par with a dramatic increase in police enforcement activity, or a $2,000 increase in DUI fines.
