If Reducing Harm Is The Goal, A Cost-benefit Analysis Shows Cannabis Prohibition Has Failed

The case for a referendum on New Zealand’s cannabis law was already urgent in 2015 when the supposedly more pressing issue was whether we should change the flag. As I argued at the time, prohibition had failed and was costing society far more than the drug itself.

As with alcohol, tobacco, prostitution and gambling, regulation – not prohibition – seemed the smarter way forward. Nothing has changed as the cannabis legalisation and control referendum looms on October 17. If anything, the evidence from five wasted decades of war on cannabis is even more compelling.

First, tens of thousands of New Zealand lives have been disproportionately damaged – not through use of the drug, but because of its criminalisation.

According to figures released under the Official Information Act, between 1975 and 2019, 12,978 people spent time in jail for cannabis-related convictions (using and/or dealing). In the same period, 62,777 were given community-based sentences for cannabis-related convictions.

These statistics have not been evenly distributed. Māori are more likely to be convicted on cannabis charges, even accounting for higher rates of use.

Each conviction represented real or potential harm to job prospects, ability to travel, educational and other forms of social opportunity.

Despite the law, cannabis use increases

Second, despite these penalties and the millions of hours of police time spent enforcing the law, demand remains stronger than ever. Mirroring international trends (an estimated 192 million people used cannabis in 2018, making it the most used drug globally), the number of people using cannabis in New Zealand is increasing.