The 1 NEWS Colmar Brunton Poll found only 35 per cent of people polled said they supported the bill, down from 40 per cent in June's poll. Those who said they did not support the bill were at 53 per cent, up from 49 per cent in June. Another 11 per cent either did not know or refused to answer.
National leader Judith Collins says the party caucus will vote no in the referendum. Prime Minister Jacinda Ardern has maintained a strict "no comment" on her voting intentions, despite admitting she once smoked cannabis "a long time ago".
So with less than a month to go to the vote, if you're undecided, here's a list of the pros and cons of what the consequences could be.
Pros: Taking control
1. Economic growth
Establishing a legal cannabis industry creates a range of skilled and unskilled jobs. It could generate more than $640 million in tax revenue for the NZ Government.
Two years after launching a legal cannabis market, California has surpassed US$1 billion ($1.5b) in tax revenue.
2. Health not handcuffs
Prohibition has not stopped New Zealanders from using cannabis. Research shows 15 per cent of men and 8 per cent of women in NZ used cannabis over a 12-month period in 2012-13.
Legalising cannabis could save the NZ justice system a staggering $11.4m a year. Not to mention the social benefit of no longer incarcerating non-violent, otherwise law-abiding citizens who then have to cope with a life-long criminal record.
Māori have higher rates of cannabis use than non-Māori. Even accounting for higher usage rates, research found Māori are more likely to be convicted on cannabis charges than non-Māori.
By legalising cannabis, use becomes an issue of health and social welfare rather than a criminal one.
3. Improves access for health patients
Cannabis is used as therapy for a number of health applications. It has been legally available for medical use in NZ since April 2020.
If cannabis is legalised for recreational use, those using it for medical purposes will have greater access at a more affordable price.
4. Regulated for consumer safety
A standard requirement for legalised cannabis markets includes product testing, which means consumers know more about the products they are using.
Cannabis bought off the street can contain fungus, harmful substances, mould and pesticides. Mandatory testing ensures the cannabis is free of toxins.
To protect children in the United States from exposure to cannabis, Alaska, Colorado, Oregon and Washington all passed child-resistant packaging regulations.
Under New Zealand's referendum, any retailers who sell cannabis to people aged under 20 would face serious penalties. To further deter youth, the NZ Drug Foundation, which is leading a yes vote, unequivocally supports the referendum's inclusion of advertising bans.
5. Takes money away from street gangs
Over the past two and a half years, street gangs in New Zealand have grown by more than 30 per cent. The illegal cannabis market, estimated to be worth $1–3b, potentially funds these gangs to some extent.
In Colorado in the US, 90 per cent of the cannabis market is supplied under regulation. Over the past decade there, cannabis seizures by border control are at their lowest levels and their value has reduced by millions of dollars.
Legalising cannabis places control of the market in the hands of the government rather then criminals.
Cons: social and fiscal
1. Unknown costs for society and taxpayers
The long-term health effects are not fully understood. Similar to tobacco, the negative health consequences of cannabis might not be realised for decades. Again, in Colorado, for every cannabis tax dollar raised, its citizens spend US$4.50 to offset the negative effects of legalisation.
2. It will turn NZ's youth to other drugs
A Christchurch Health and Development study shows adolescent weekly users of cannabis were 100 times more likely to use other illicit drugs.
3. Workplace safety and productivity
A 25-year study in Norway shows workers who use cannabis are less dedicated to their work than those who don't.
In the US, cannabis use by employees leads to increases in absenteeism, accidents, job turnover and worker compensation claims.
4. Bad for the environment
Cannabis plants require double the water needed to grow grapes for wine. Growing cannabis may cause deforestation, habitat destruction, river diversion and soil erosion.
When grown hydroponically, yearly greenhouse gas emissions in the US equal that of 3 million cars.
5. Property prices could rise, or fall
Once again in Colorado in the US, legalising cannabis was found to increase the value of property prices by up to 6 per cent.
A separate study in Colorado found house prices could increase by up to 8.4 per cent if they were within 160m of a retail outlet selling cannabis.
But 42 per cent of Canadians believe a cannabis retailer will negatively affect their home values.
There are just over two weeks to go now before New Zealanders vote on the cannabis referendum. If you still can't decide, then head to the Prime Minister's Science Adviser website for more information, or watch the video below.
Patrick van Esch is a senior lecturer in marketing at AUT Business School; Michelle O'Shea is a senior lecturer in management at Western Sydney University; Sarah Duffy is a lecturer at the School of Business, Western Sydney University.