Opinion as well as science informs policy advice

The Christchurch Health and Development Study found  80% of the cohort, now aged 43, had tried...
The Christchurch Health and Development Study found 80% of the cohort, now aged 43, had tried cannabis. PHOTO: REUTERS
Prof Joe Boden, of the University of Otago Christchurch, provides a view from inside the expert panel on cannabis ahead of this year’s cannabis referendum.

Joe Boden. Photo: Supplied
Joe Boden. Photo: Supplied
A year ago several New Zealand academics, me included, were invited to join the expert panel on cannabis by the Prime Minister’s Chief Science Adviser, Prof Juliet Gerrard.

With the referendum on the legalisation of cannabis planned for this year, the Prime Minister had asked Prof Gerrard to assemble the panel in order to present research on cannabis, cannabis-related harm and cannabis law reform to New Zealanders in an accessible manner.

The panel, comprised of academics ranging from public health, to addiction medicine, law and economics, met for the first time in September last year, and for the last time during the Covid-19 lockdown in May (via Zoom). Our report was published online on July 7.

Serving on the panel was a fascinating learning experience.

In academia, as with many jobs, we tend to spend much of our time working in our departments and research groups, and relatively little interacting with experts in other areas.

In this case, however, we had the privilege of spending large amounts of time talking through each of our own areas of expertise, learning a great deal along the way, and working out the best way of presenting the most important information to the public. To this end we were ably assisted by the staff of the Office of the Chief Science Adviser, who made the process run almost seamlessly for us.

Given the broad scope of our brief, and the resulting report, it would be almost impossible for me to encapsulate our findings in a short article such as this.

However, the report itself has been presented in such an accessible and plain-language manner that I would be unable to improve upon it. I believe it serves as a valuable tool for the general public to understand the research on cannabis, and what is likely to happen in the case of either a Yes or No vote winning the referendum.

A key aspect of the report is that it takes a politically neutral stance, but members of the panel were not required to be politically neutral.

This has drawn some criticism, particularly from prominent ‘‘No’’ campaigners, who accused the panel of being ‘‘biased’’.

This reflects, I believe, a misunderstanding of the notion of scientific objectivity. It is true that our roles as scientists and academics require us to consider all evidence in a manner that is unbiased as possible, and we have done so as panel members in the way we normally carry out our roles.

However, many of us working in applied fields such as health are also required as part of our normal roles to form opinions regarding policy as a result of that evaluation.

As an example, as a researcher funded by the Health Research Council, I am obligated to interact with policymakers, providing recommendations about what policies should look like. This task requires that I form an opinion based on the evidence, and this is true of cannabis policy as much as any other policy.

Having said this, I do have an opinion as to what is the best policy to deal with the issue of cannabis, which I formed some time ago on the basis of my reading of the evidence. My view is that the best approach is encapsulated in the proposed Cannabis Legalisation and Control Bill, which will legalise and strictly regulate the already-thriving (but mostly prohibited) cannabis industry.

There are many reasons why I have formed this view, but the following are the most prominent.

First, our own research with the Christchurch Health and Development Study has shown that 80% of our cohort of now 43-year-olds have tried cannabis, suggesting that the law does not prevent use.

Second, a further study of our cohort showed that 95% of those arrested or convicted of a cannabis offence either continued to use cannabis at the same level, or increased their use, suggesting that having the force of the law applied to you is not a deterrent to cannabis use.

Third, our study also found that Maori were three times more likely to be arrested or convicted of a cannabis offence, showing that the law is being applied in a biased manner.

All three of these considerations show that the law does not work to prevent cannabis use as intended, and in fact causes more social harm than it prevents, which is why I am in favour of changing this law to a much more sensible and health-centred approach.

 - Prof Joe Boden is director of the Christchurch Health and Development Study at the department of psychological medicine, University of Otago, Christchurch.