A study published in the scientific journal Addiction provides the most comprehensive evidence to date of the association between recreational cannabis laws (RCLs) in US states and responses in the illegal markets for cannabis, heroin, and other drugs in those states.
As of 2021, 17 US states and the District of Columbia have implemented RCLs that allow people aged 21 and older to possess, use and supply limited amounts of cannabis for recreational purposes. This study found that the implementation of RCLs was associated with the following responses in the illegal drug market in those states:
- 9.2% decrease in street/illegal cannabis prices.
- 19.5% decrease in low-quality street/illegal cannabis prices.
- 64% increase in heroin prices.
- 54% increase in heroin potency.
- 7.3% increase in street/illegal oxycodone prices.
- 5.1% increase in street/illegal hydrocodone prices.