TL;DR:
- Alcohol $7.8b
- All illicits: $1.8b
- Meth: $0.365b
I wanted a figure for cannabis and found this from 2020:
- All illicits: $1.9b
- Meth: $0.824b
- Cannabis: $0.911
I notice that the per kilograms measure for harm is also useful to account for volume of usage, but think that per ‘dose’ would be better.
- Meth: $1.1m per kg with 743kg consumption
- Cannabis: $0.35m per kg with 58000kg consumption
These figures include ‘associative crime’ as harm. So it apparent counts the cost of buying it as harm, it also counts the tax loss of that expenditure, so IMHO it skews unfavourabley to higher expenditure. But put that aside.
These figures show that all illicit drugs combined are less harmful to society than alcohol, and tautologically the harm is inflated by illegality.
What is this massive increase of usage you assume would happen? All drugs could be legalised without offering them for sale with minimal checks like alcohol currently is.
I’m not sure there are huge numbers of kiwis just itching to get a meth habit, if only it were legal.
I don’t think there is anyone out there, who is not starting a meth habit because it is illegal.
But lowering of social stigma, no chance of a criminal record and knowing you will get clean product; all will put upward pressure on usage numbers.