Looks like another episode in the failed war on drugs. While this may look “good” and someone will be able to say “look at those figures” in reality we’re addressing a side effect of a much deeper issue.
In that regard: keeping a black market for drugs may even be a good thing. Otherwise they'd move on to other ventures that might be more harmful, kidnapping, murder for hire etc.
Furthermore, you're suggesting that when their way of making money through crime disappears they will migrate towards worse crime. That's a bold claim.
I am not positioning myself here, but I would say if this was a "failed war" on drugs things would be different. Just take a look on how things look like in some regions of Central America.
For anyone interested, a show recommendation: The Wire by David Simon
Did they actually throttle the supply? Did it rebound? How quickly? These are the interesting questions yet I don't see them reported.
A good book on this is 'Narconomics: How to Run a Drug Cartel' by Tom Wainwright
- Personal reports from drug users
- since the majority of users are recreative users and not hardcore junkies, and even those are just people with various levels of mental issues, I would actually find this reliable.
- There are surveys that are taken, at least here in the EU, that track drug usage.
- Quality sampling of confiscated drugs
- Analysis of medical data (deaths, overdoses,...)
- Analysis of police data (crimes related to drug usage)
A lot of data out there.