One of the main real external costs of alcohol use comes via alcohol-associated crimes. And so it's good to see the government attempting a more finely tuned intervention on this than using excise tax.
David Farrar points to the Drug and Alcohol Testing of Community-based Offenders and Bailees Legislation Bill coming up. In short, it allows drug and alcohol testing to be a condition of bail.
Why is this a good idea? Something similar seems to have done a lot of good in Hawaii. Here's Heritage on the Hawaii Opportunity Probation with Enforcement (HOPE) project, which targeted methamphetamine users, and here's an evaluation of South Dakota's programme that targeted alcohol use.
To be very clear: I only support this kind of thing for offenders who have committed real violent or property crimes, and not those caught simply for drug possession.
But for those offenders who go out and do bad things to people while drunk or high, well, they've probably well signalled that they should be kept away from the stuff for a while.