Cannabis-derived drugs are among the most widely used illicit substances in the world

The handful of existing attempts to model outcomes from cannabis law reform in New Zealand have faced significant domestic and international data limitations, most importantly the limited data on cannabis legalization implemented over- seas . As described earlier, we utilized the NZ-DHI estimates of the health and social harm of cannabis as the starting point for our MCDA model. While this report had access to national statistics on cannabis use and harm, there remained gaps in data and, as a result, simplifying assumptions had to be made to complete the estimates . A number of these assumptions are controversial, such as the decision to split the remaining 64 drug related deaths that could not be assigned to opioid overdose or psychedelics evenly between amphetamines and cannabinoids . This decision may be linked to the inability at the time to separate natural cannabis from synthetic cannabinoids in official statistics, as synthetic cannabinoids have been linked to a number of over- doses in New Zealand .

Furthermore, mobile grow systems all the acquisitive crime committed by people with cannabis dependence is as- signed to cannabis harm without determining the causal role cannabis use may have played in motivating these offences. Second, as noted at the beginning of this paper, one of the recommendations from the recent MCDA of drug policy is to broaden the decision- making group . Our MCDA achieved this objective to an extent by including officials from a range of government agencies and NGO workers concerned with drug and health issues, including M āori, cannabis legalization activists, medicinal cannabis industry, drug treatment and mental health, and law enforcement organizations. This could be taken further to include those most affected by the current cannabis prohibition and reform options, including youth, M āori, Pasifika, parents of adolescents, and those living in high deprivation communities. To ensure the views of these affected groups are not swamped by the majority view in a combined workshop, a series of MCDA workshops could be conducted with each entirely com- promising members of one of the affected groups . While we were not able to convince the main anti-cannabis legalization activist group to attend the MCDA, we had a range of government and NGO stakeholder participants who may have been am- bivalent, or even opposed, legalization .

The refusal of the main antileglization group to attend may reflect their view, wrongly held in this case, that the forum is not interested in their perspective or values. Indeed, the rejection of the NZ cannabis referendum has in part been explained by a failure to engage with conservative right-wing voters about how cannabis legalization may align with their political values cannabis grow supplies. Anti-legalization groups may well have supported the current prohibition approach and more in- vestment in drug treatment and prevention. This option was not part of our MCDA policy options as we were primarily aiming to inform the de- bate around the cannabis referendum which was specifically concerned with the legal status of cannabis use and supply, not wider policy set- tings addressing cannabis harm under the current prohibition, such as increasing the level of funding of treatment and prevention. Third, MCDA is an instrumental group decision making tool that focuses on tangible outcomes of policy decisions. Moral views of cannabis use were found to play an important part in how people voted in the NZ cannabis referendum and likely influenced how stakeholders voted in the MCDA trade-offs. Yet, as outlined earlier in this paper, the purpose of MCDA is to facilitate group decision making concerning controversial policy issues by asking participants to consider tangible trade-offs in outcomes to reach pragmatic compromises. The closeness of the final NZ cannabis referendum result  illustrated both significant support for reform and concern about the specific reform proposal put forward for the referendum vote .

The CLCB most closely resembled the “strict market like tobacco ”option in our MCDA. Our MCDA results suggest a higher stakeholder support for two even more restrictive legal market options, “government monopoly ”and “not-for-profit ”trusts. According to the 2021 World Drug Report, it is estimated that over 200 million people have used cannabis globally, likely increasing amid the global COVID-19 pandemic . However, efforts to decriminalize, legalize, and reclassify the scheduling of these drugs are fast transforming the landscape of cannabis use and research. Despite the UN’s reclassification of cannabis and its derivatives, these drugs remain classified as schedule I by the US Drug Enforcement Administration together with other drugs such as heroin, and ecstasy . Moreover, the perceived decrease in the risks associated with cannabis use has contributed to its popularity and increased usage, already exacerbating a global health problem .