In preparation for New Zealand’s September 19 referendum on cannabis, all sides of the debate are sharpening their lines of argument.
Often, both the proponents and detractors of cannabis reform point to examples in the United States to bolster their position. But in the whirlwind of online debate, fact-checking is more of an option than a prerequisite, unfortunately.
Some of the best data on the effects of cannabis reform does come from the US. Many states have had medical marijuana laws since the 1990s and legalisation of nonmedical use since 2012.
This page is meant to be a touchstone for anyone looking for speedy – and accurate – information on what exactly is happening in the US. This project has pulled all the relevant cannabis reform data from each of the 50 states, drawing on a range of sources at both the federal and local levels.
The resulting data is loaded into the map of the US below.
Please, click around to learn more.
The US is essentially 50 real-time, parallel public policy experiments. While many federal laws apply nationwide, local US state governors have plenty of flexibility in setting their own policy.
Some US states began dealing with cannabis 100 years ago, while others have only just tabled the issue in the last few years. The debate has picked up steam across the country recently: a Gallup poll conducted in 2018 found that 2 out of every 3 Americans support legalising cannabis.
And cannabis has also grabbed the attention of big business. Cannabis, or marijuana, is being used by the cosmetic, pharmaceutical and food and beverage industries. The US cannabis market size was valued at $US11.3 billion in 2018 and is expected to follow a compound annual growth rate of 14.5% out to at least 2025, according to a study by Grand View Research.
At the close of 2019, 33 US states now allow marijuana for medical, recreational or both purposes. The 2018 Farm Bill, which legalised the cultivation and sale of hemp and hemp oil, has helped cement the idea for many governors that it is time to rethink cannabis policy.
However, the market is not quite mature enough yet. The Bank of New York Mellon, one of the largest custody and clearing banks in the world controlling $US35.5 trillion in assets, announced in October 2019 it would stop accepting positions or trading with US marijuana-related businesses citing concerns with the standards of anti-money laundering processes.
And on measurements such as violent or property crime in states which have legalised cannabis, the data shows a downward trend in those crimes tends to begin before the decriminalisation of cannabis comes into force. Many academics and research institutes have looked into the relationship of law changes and a drop in crime. So far, a 2019 study by Ruibin Lu, et al, showed “no statistically significant long-term effects of recreational cannabis laws or the initiation of retail sales on violent or property crime rates” in the two US states which first legalised the drug – Washington and Colorado. Those two states have the greatest volume of data.
The authors also note there is no way to tell if increased use of cannabis will affect crime rates over time.
The interactive map below displays many of those trend lines clearly and outlines how the 50 states have dealt with cannabis.
 Two in Three Americans Now Support Legalizing Marijuana, Gallup, October 22, 2018: https://news.gallup.com/poll/243908/two-three-americans-support-legalizing-marijuana.aspx
 US Cannabis Market Size, Share & Trends Analysis Report By Cannabis Type (Medical, Recreational), By Product Type (Buds, Oils, Tincture), By Medical Application, (Chronic Pain, Mental Disorder, Cancer), And Segment Forecasts, 2019 – 2025: https://www.grandviewresearch.com/industry-analysis/us-cannabis-market
 Ruibin Lu, Dale Willits, Mary K. Stohr, David Makin, John Snyder, Nicholas Lovrich, Mikala Meize, Duane Stanton, Guangzhen Wu & Craig Hemmens (2019) The Cannabis Effect on Crime: Time-Series Analysis of Crime in Colorado and Washington State, Justice Quarterly, DOI: 10.1080/07418825.2019.1666903
Interactive map of cannabis reform across the US: