With marijuana legalization ending 95 years of prohibition in Canada, adults across the country can now buy, consume and grow cannabis. But it's not the only place in North America where you can legally light up.
On Jan. 1, 2014, Colorado rang in the New Year by celebrating the birth of a legal weed regime in the state. The industry quickly grew, with reports of Denver famously sprouting more dispensaries than Starbucks.
Four years later, what does the data from Colorado show, and what can Canada learn from the state's experience?
Did more people start using pot?
The legal age to use cannabis in Colorado is 21, just like the drinking age.
Two different public health surveys show that after legalization, there was no jump in consumption among high school students.
Jack Reed, a statistical analyst with the Colorado Department of Criminal Justice, called this trend "very encouraging."
"The fact they converge and show no increase in youth use, that's very encouraging," he told CTV News from Denver. "We're happy about that."
Data also shows that the average rate of Colorado youth who use weed was about 19 per cent in 2017, roughly on par with the national average of 20 per cent.
Adult usage hasn't seemed to spike either. Between 2014 and 2016, adult usage rates held steady at about 13.5 per cent, before increasing slightly to about 15.5 per cent in 2017.
Did crime go down?
The data from Colorado says a few different things about crime after legalization.
The first thing to note, says Reed, is that thousands fewer people are picking up minor charges for possession. The legal limit in Colorado is 1 ounce, or approximately 29 grams.
Since legalization, the number of minor possession charges has plummeted, dropping more than 90 per cent compared to 10 years ago.
For more serious charges such as manufacturing, distribution and possession with an attempt to sell, the number of charges decreased immediately after legalization. However, they have since rebounded up to pre-legalization levels.
This indicates that legalization hasn't completely stamped out the black market, says Reed.
Prof. Sam Kamin, a professor of marijuana law and policy at the University of Denver, says part of the black market likely consists of the re-sale of Colorado weed to other states where it's still illegal.
In the U.S., marijuana is illegal under federal law but it has been legalized in eight states: Alaska, California, Colorado, Maine, Massachusetts, Nevada, Oregon and Washington. It has also been legalized in Washington, D.C.
In contrast, Canada has legalized weed nationwide.
"In Canada you'll have a very different situation, where you're legalizing at the national level with more cooperation between the federal and provincial governments," Kamin told CTV News from Denver.
Did more people drive high?
The number of DUIs across Colorado has been generally declining over the last 10 years, and this has continued since after legalization in 2014.
Before legalization, the data for impaired driving arrests and charges did not separate alcohol and marijuana impairment. But since 2014, DUI data separates cases of drug, alcohol and marijuana impairment.
Generally, the percentage of DUIs involving marijuana (either by itself, with alcohol, or with other drugs) has varied between 11 per cent to 16 per cent.
"What we're seeing is not necessarily a huge increase in the prevalence of it as far as we can tell," says Reed.
Does legal weed bring in a lot of tax revenue?
The amount of revenue brought in from taxing and licensing weed has risen every single year in Colorado since 2014.
In 2017, weed brought in more than US$247 million in taxes and licensing fees.
In Colorado, there is currently a 15 per cent retail sales tax on recreational marijuana, as well as a 15 per cent excise tax. For medical marijuana, there is a sales tax of 2.9 per cent.
Kamin says while legal weed generates a lot of tax revenue, it hasn't yet proven to be the kind of money that can disrupt an economy.
"That's a lot of money," he said. "But we also have a $28-$29-billion state budget, so marijuana really accounts for less than 1 per cent."
Also, he says, governments should be wary of raising taxes on weed to bring in more funds, as that could lead to the rise of the black market.
"While it does bring in some revenue, it's not the sort of game-changing revenue you might see in other areas," he said.
"I think the Canadian government should see revenue from (marijuana) as a bonus rather than a reason to do it."
Data, data, data
Both Kamin and Reed agree that collecting good data, and starting early, is critical when it comes to legalizing pot.
"It's really important to have good metrics to measure all the things you might be interested in, (from) impaired driving, to youth usage rates," Kamin said.
It's also a good idea to measure things that are not necessarily associated with weed, he added.
"Marijuana usage gets blamed for the homeless rate here, gets blamed for the property values going up," he said. "The better and more metrics you have, and the earlier – the more pre-legalization data you have, the easier it will be to measure going forward."
Also important, Kamin says, is an understanding that legalization is a work in progress that requires continual revisiting and tweaking of policies.
"It's not something you pass laws (on) and that's the end of it," he said. "If you're not willing to commit those types of resources to sticking with it, you're not going to get the results."
More stories:
• Colorado experienced a 'sharp spike' in ER visits after legalizing cannabis: doctor
