Do Long Sentences Deter DUIs?

Kansas Gov. Kathleen Sebelius signed a new law yesterday increasing the state's penalties for driving under the influence of alcohol - requiring a minimum sentence of 180 days in jail for a fourth conviction. Penalties across the country vary - while some states, and certain judges, are much tougher on repeat offenders, there are thousands of people out there with four or five DUI convictions and a slap on the wrist. The Milwaukee Journal-Sentinel reported last fall that only half of people in Wisconsin convicted of their fifth DUI served time in prison.

Isn't there a disparity here between drug possession, which is only a danger to the user, and drunk driving, which is a danger to society? Drunk drivers kill 250 people a week in this country. A third conviction for crack possession could bring 20 years in prison in federal or state courts. A third DUI in Kansas gets 48 hours in jail and house arrest.

Doug Berman, who usually advocates smart sentences over long sentences, has posted frequently about this disparity and has called for harsh punishment for repeat drunk drivers. In October, he wrote:

I think drunk-driving sentences should start getting pretty tough starting with the second conviction, and I would be fine with a "three-strikes-you're-out" approach to this crime that contributes to the deaths of so many innocent persons and many related social harms.  But I find it both troubling and telling that defendants facing sentencing for their fifth conviction for drunk driving are still more likely to receive probation than a prison term.

Here's another SL&P post with some interesting discussion of the issue.

I agree with Doug that there's a disparity between drug sentences or sex offense sentences and those for drunk drivers. But do long sentences really deter drunk drivers? I often argue that we're warehousing non-violent drug offenders with ineffective long sentences. Treatment would stem drug abuse where 10-year sentences don't. Isn't it the same for drunk drivers?

One study in Alberta found that extending sentences up to six months in prison did have a deterrent effect, but that time over six months wasn't a deterrent. I think the answer may lie not in longer sentences, but in alternatives, like interlock devices (in-car breathalyzers). These devices are more than a deterrent, they physically prevent drunk driving - the car won't start if you blow anything over a .00. The Tennessean argued this month for increased use of the devices, and pointed out that the main opposition comes from the American Beverage Institute. Not exactly an impartial observer. I would support mandatory interlock devices after a first offense. They won't stop the repeat offenders who drive without a license, but they will decrease drunk driving deaths and accidents.

I'm less comfortable with checkpoints, however, which also seem to be increasing in use around the country. While they probably are an effective deterrent, they also increase contact with law enforcement and therefore lead to discriminatory arrests and other issues.