Cannabis referendum: Most voters 'not prepared' to vote according to evidence - expert

One of New Zealand's top public health researchers is "disappointed" the question of whether recreational cannabis should be legalised is going to a referendum, saying most people don't have the knowledge to make an informed decision.

When people vote in this year's general election - whenever that might be - they'll also be asked whether they support the legalisation of the popular drug, which around 80 percent of Kiwis will use at some point in their lives, according to studies.

The vote is non-binding, and a Bill outlining how a legal market in New Zealand would work would still have to go through Parliament, even if Kiwis vote 'yes'.

Joe Boden, deputy director of the long-running Christchurch Health and Development Study and a research professor at the Otago University's Department of Psychological Medicine, will be voting yes.

"Public health researchers such as myself, almost none of us believe criminalising drug users - whatever drug they use - is a particularly productive strategy," he told Magic Talk's Sunday Cafe. 

But it's not just public health researchers that will get a say. 

"I'm really disappointed that we're having a referendum about this, to be honest," Prof Boden said.

"It's not really most people's business to be reading studies and trying to make sense of data. That's why we've spent a great deal of time creating public-facing resources that try to present data to people. 

"I suppose allowing people to make the choice is participatory democracy, but you're really giving people a job to do that they're probably not prepared to do." 

He fears many voters will make their choice based on anecdotal evidence and their own personal experiences, rather than what the evidence suggests.

"Unfortunately the plural of anecdote is not data. It's almost impossible to try to make an evidenced, informed decision when this is the level of discourse around things."

Anti-legalisation activists fear it will lead to an increase in harm, particularly amongst young people. Prof Boden argued that wasn't evident in overseas jurisdictions that have decriminalised or legalised cannabis, or other drugs. 

"We generally are most worried about young people because they're the most vulnerable to the negative effects of substance use, whether it's alcohol or cannabis. 

"Most of the so-called doom-and-gloom scenarios that have been put forward rely on the assumption that use will increase quite dramatically, so therefore harm will increase quite dramatically - except that around the world, wherever it's been decriminalised or legalised, use hasn't increased dramatically. 

"It hasn't increased dramatically particularly in vulnerable young age groups. Where it has increased to some extent is typically in middle-aged people - and honestly, for middle-aged people, it's probably pretty safe." 

Young Kiwis are actually drinking and smoking less than they used to, he said, and legalisation will help reduce the risks cannabis poses to their developing brains.

"Young people who are using more often and more heavily are less likely, for example, to complete their education, and more likely to go on to use other illicit drugs and are more susceptible to symptoms of psychosis... One of the things we're most concerned about is keeping it out of the hands of young people, which is a bit difficult when it's not legal but it's also not regulated."

When asked why legalisation instead of decriminalisation, Prof Boden said a law change last year effectively directed police not to arrest and charge users - de facto decriminalisation - but they basically ignored it.

"Police were meant to treat drug possession as a health issue, rather than a criminal issue, and were required by the change in the law [to show arrests and convictions were in] the public good. But the data released by the New Zealand Herald a couple of weeks ago show the police aren't doing that... The police don't seem to have got the memo." 

The election and referendum is currently scheduled for September 19. Prime Minister Jacinda Ardern is expected to announce on Monday whether it will go ahead on that day, or be delayed thanks to the recent outbreak of COVID-19 and resulting lockdown in Auckland.