Collecting an extra $150 million a year in tax revenue at a time when the health, education and housing sectors are all screaming out for money – sounds like a no-brainer, right?
The catch? Legalising cannabis.
This week Nelson lawyer Sue Grey revealed through an Official Information Act request some informal notes from Treasury, which calculated that legalisation would not only generate money, but also save $400m a year on enforcement of drug prohibition.
Treasury noted two options for dealing with drug reform. First, decriminalisation, which would satisfy international treaties by keeping drug use illegal but with criminal penalties swapped for civil penalties, such as rehabilitation treatment for people who need it.
The full-throttle option is legalisation, which means the Government could generate revenue from the sale and production of some drugs while reducing enforcement costs further.
STACKING UP THE EVIDENCE
Treasury says, particularly for lower-harm drugs already widely available, "this wouldn't have any big negative impacts".
It notes a number of countries are already moving in this direction. Denmark, Germany, Portugal and parts of Australia and the United States have all decriminalised the possession of cannabis to varying degrees.
"Their experiences have been positive and don't seem to have increased drug use."
Treasury also noted drug reform isn't a "particularly radical idea these days".
"It's supported by The Economist and the Global Commission on Drug Policy, as well as reports by our health select committee and the Law Commission."
So now that information dating back to 2013 has gone public and people are talking about it, what is Treasury's position?
A spokesman says money saving/generating from cannabis hasn't been part of any formal work programme.
There's been no formal analysis and the document was simply "high-level estimates from a variety of sources" but did not undergo the process of quality assurance as other policy would.
In short, "it was a conversation starter" – apparently a common practice at Treasury to test ideas that are floating around.
GOVERNMENT'S SPLIT OPINION
So will Treasury take the idea further? No, says English.
The minister's office says Treasury has not been asked to do any further work on this – in other words, the Government has no interest in pursing the legalisation of cannabis.
And, personally, English doesn't favour legalisation either.
So why no appetite from the Government?
There's plenty of theories, from it being political dynamite especially for a third-term government, to concerns the drug and alcohol bods will revolt given that decriminalisation and legalisation often lead to a downturn for those industries.
But there's one member of the Government who is a bit rogue on the issue. Admittedly UnitedFuture leader Peter Dunne isn't a National Party member, but he is a minister and he's the one in charge of signing off on medicinal cannabis applications.
Dunne "respects" that the Government has no interest in changing the legal status of cannabis but in his own view that position is the wrong one.
"If you can grow a natural product in your backyard and someone else can manufacture something that's equivalent to that product, and the manufactured product can then be submitted for testing and be judged to be low risk and put on the market for sale, why can't you do the same with the natural product?
"That's the thinking. Now of course things aren't as simple as that, but as a principle I think that's where I would see this heading," Dunne says.
What he's talking about is the Psychoactive Substances Act once it's fully implemented. As to when that will be, it's like asking how long a piece of string is, says Dunne.
"The real issue here is that we have not been able to finalise the testing regime because Parliament, quite properly, moved to ban animal testing. So at some point the international community will move similarly to ban animal testing, not just for psychoactive substances but across the board, so therefore alternatives will have to be developed."
At that point, Dunne says, the regime will come "back into play" but that could be two, 10, 15 or even 20 years away.
So from his perspective, once the act is fully operational cannabis will be able to be tested in the same way as any other drug is and "if it is deemed to be low risk and can be sold under the same conditions, i.e in R18-designated stores" then he says that's the right approach.
"But we're not at that point."
FINDING ANOTHER WAY
Grey says an easy way to deal with cannabis, similar to how there are exemptions for drugs like morphine, would be to add it to regulation 22(2) of the Misuse of Drugs Regulations.
Regulation 22 prevents any doctor or other person administering any controlled drug to any person without the prior approval of the minister.
But the second part of the regulation creates an exemption for cocaine-based medicines and morphine products.
"It would then be for doctors to prescribe whatever medicine they consider to be the most fit for purpose for the patient, depending on the needs of the patient," Grey says.
"We trust doctors to make life-saving decisions for patients on a wide range of conditions, so this simple amendment would put cannabis on a similar footing to other medications."
Former Council of Trade Unions president Helen Kelly echoes Grey's push for medical professionals to make the decisions, rather than ministers.
Kelly, who was diagnosed with terminal lung cancer almost 18 months ago, has been illegally taking cannabis for many months. She says it has allowed her to keep living her life pain free.
"Cannabis isn't a bad drug. I don't think it's good for teenagers, but I think we can regulate, control and understand it," she says.
Grey is working with Kelly to help her get access to prescribed cannabis products overseas that she can bring back to New Zealand thanks to a loophole discovered by Grey's client, Rebecca Reider.
The Golden Bay woman won a legal victory when she escaped conviction after being charged with importing medicinal cannabis products.
So as laws start to crack around medicinal cannabis, what's the argument against decriminalisation or taking the leap to legalisation?
WHAT ARE THE HEALTH EFFECTS?
Scientists in the United Kingdom, US, Europe and Australia are warning that frequent use of cannabis can increase the risk of psychosis in vulnerable people at the same time as many of those governments are moving towards decriminalisation.
The Royal College of Psychiatrists warns cannabis can trigger mental health problems in people who seemed to be well before, "or it can worsen any mental health problems you already have".
"The younger you are when you start using it, the more you may be at risk. This is because your brain is still developing and can be more easily damaged by the active chemicals in cannabis."
Given most experts consider a brain not to be fully developed until the age of 25, having cannabis legally available in R18 stores could have a substantial effect on the mental health system.
An Otago University report, Cannabis use in adolescence, by David Fergusson and Joseph Boden says cannabis is the drug most commonly used by New Zealand adolescents.
"Estimates suggest that by the age of 21 in the region of 80 per cent of young people will have used cannabis on at least one occasion, with 10 per cent developing a pattern of heavy dependent use."
There is increasing evidence that regular or heavy use of cannabis leads to increased risks of mental health problems, other forms of illicit drug use, school dropouts and educational under-achievement, motor vehicle collisions and injuries, the report says.
GREY POWER WANTS ACCESS
Health concerns aside, Grey Power is one of many voices throwing their weight behind loosening the rules around cannabis.
A group of Northland retirees who say they have never taken illegal drugs are petitioning for medicinal marijuana on the basis the elderly should have the choice to die pain free.
When the group went public about their petition, the Cannabis Party decided to join the fray, which reportedly led to Grey Power national president Tom O'Connor having a "heated stoush" with the party when he told them to stay out of Grey Power matters.
It is understood O'Connor wasn't interested in a party pushing for legalisation of cannabis for recreational purposes joining a Grey Power local chapter's campaign for medicinal marijuana.
For the past two years medicinal cannabis has been hitting the headlines hard.
It really gained momentum in April last year when Nelson teenager Alex Renton was approved Elixinol, a cannabidiol product from the US, by Dunne.
Since then it's been revealed the late Paul Holmes and Martin Crowe were both using cannabis for pain relief in their final months.
Grey is calling for medicinal cannabis law reform to be an election issue when voters go to the polls next year.
"Cannabis law reform may just become New Zealand's equivalent of Brexit – the issue which empowers the public to make their voice heard."