Cannabis Referendum

Cannabis referendum information

Office of the Prime Minister’s Chief Science Advisor: Legalising cannabis in Aotearoa New Zealand: What does the evidence say?

Professor Joseph Boden: What 40 years following thousands of NZ people tells us about cannabis harm

The Royal Society Te Apārangi has got resources on Cannabis health impacts

The Cannabis Referendum 2020 – some key issues

Professor Joe Boden Department of Psychological Medicine, University of Otago, Christchurch

On 17th October, alongside the general election, New Zealanders will also get to vote on two referendum questions. One of these questions is about the legalization of cannabis for personal use, under the terms of a bill drafted by the Ministry of Justice (the Cannabis Legalization and Control Bill). In the event of a majority “yes” vote, the Bill will then make its way through the normal legislative channels, where it will be debated, and where public submissions on the Bill will be sought. From my own perspective as an academic psychologist and researcher in the antecedents and consequences of cannabis use in a longitudinal cohort (the Christchurch Health and Development Study), I believe there are a number of key issues to consider when thinking about how to vote on this issue. I have outlined each of these as questions, with a brief description of what we know, and what we expect might happen if cannabis is legalized.

1. Will cannabis use increase if we legalize it?

This is a question that is asked frequently, and the answer is that it is unclear what will happen. Changing a law such as cannabis prohibition is a social experiment, and as such it is difficult to predict the result. Overseas, what has happened is that use has not gone up for young people, whom we believe to be most vulnerable to cannabis-related harm. There has been evidence of increased use in other age brackets, such as middle-aged men in Canada, but many researchers believe that cannabis use is safer for adults than for young people. Given the fact that cannabis use is common in New Zealand, with around 80% of both the Dunedin and Christchurch cohorts reporting having used cannabis, it is difficult to see how the market for cannabis will grow after legalization – anyone who wants to use it now can access it quite easily.

2. Will there be an increase in cannabis-related harm?

Many of the arguments against legalizing cannabis have focussed on the harm caused by problematic cannabis use, including harms to mental and physical health, and risks of accidental injury or death due to drug-impaired driving. It is important to note however that an important premise in these arguments is that harms will increase because cannabis use will increase. As noted above, it is not a certainty that cannabis use will increase in this way.
Irrespective of these arguments, it is possible that cannabis legalization as outlined by the Bill will reduce harm rather than increase it. First, the proposed legal cannabis regime has an age limit of 20, meaning that adolescents will not be able to purchase cannabis, which has been shown to be an effective means of reducing access to substances in young people (particularly tobacco and alcohol). Second, under the Bill cannabis will be sold in licenced premises, which will be required to display health and safety information pertaining to cannabis use. Third, all products sold will be tested both for purity and for THC/CBD content, so consumers will know that they are buying a safe product, and will know the levels of psychoactive content in the product. Fourth, the Bill makes provision for ring-fencing some of the tax levied on cannabis products for the purposes of increasing funding for programmes to help people deal with problematic drug use. Finally, some very real measure of harm reduction will be achieved by no longer arresting people for cannabis offences and subjecting them to the justice system.

3. Will big overseas corporations get involved in the cannabis trade in New Zealand?

This is a key concern for many, as we have seen that when multinational corporations sell psychoactive substances (such as alcohol and tobacco), there is constant pressure to grow the market and increase use in the population. Therefore, an important part of cannabis legalization is finding ways to both have an open legal market, but to keep that market from growing to any major extent that it would attract overseas investment. In order to address this issue, the Bill proposes a suite of controls designed to eliminate the likelihood that we will have big overseas corporations involved. First, the Bill stipulates that licences to participate in the cannabis industry (whether as a producer, wholesaler or retailer) will be issued only to New Zealand-based companies. Furthermore, the Bill prohibits any vertical integration of businesses involved in cannabis production and sale. This means that a licensee can only operate one kind of cannabis-related business – growers cannot also be retailers, for example. Also, the Bill limits the involvement of any single entity to no more than 20% of the total share of any aspect of commercial cannabis. In addition, the Bill does not allow importation of cannabis, and places a limit on the amount of cannabis that can be produced in any given year, to impede market growth. With these strict controls in place, it is difficult to see how large multinational corporations would envision much profit to be made from a legal cannabis regime in New Zealand.

4. Will legalizing cannabis “normalize” its use?

Another argument that has been made in the lead-up to the referendum is that we should not legalize cannabis because using it will become normalized. To an extent, evidence from overseas has suggested this is correct. In states where cannabis has been legalized in the US for example, attitudes toward cannabis have changed, with perceptions of the risks associated with cannabis use decreasing in more recent surveys. Having noted this, it is worth pointing out a few issues with the idea of “normalization”. First, as noted above, cannabis use is already a normal part of life in New Zealand, with the majority of the population having tried it, and with extensive experience with cannabis in some age cohorts. Second, normalization is actually a good way of reducing the stigma associated with the use of drugs. The use of drugs, in particular illicit drugs, is often heavily stigmatized, and this stigma serves as a barrier that keeps individuals from seeking treatment for substance use problems. If cannabis use were normalized, then people who are using cannabis problematically will be more likely to discuss their cannabis use with their GP or other health professional. Third, it is unlikely that normalization will lead young people to think that using cannabis is “ok”. Tobacco and alcohol are legal drugs – for adults – and young people are routinely discouraged from using these via education programmes, media, and their families. There is little reason to expect that cannabis would be any different.


In October we all get a chance to vote on what I have referred to as a social experiment. When deciding how to vote, it might be helpful to consider the fact that we are not voting on whether people should use cannabis. That issue has been settled by reality; cannabis is here and it is commonly used, and will continue to be commonly used irrespective of the result of the referendum. What we are voting on is whether we want to take control of an unregulated market, and put cannabis use in its proper perspective as an issue related to health and personal choice, rather than a criminal justice issue.


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