A new report evaluates marijuana legalization in Colorado so far. It's mixed news.

Will marijuana legalization in Colorado cause pot use and abuse to skyrocket, along with other problems associated with cannabis? Or will it be a net gain, creating new jobs in a burgeoning industry while cutting arrests for a relatively mild drug?

A new report from Colorado finds a little bit of the first and a little bit of the second.

The report, filed by the Colorado Department of Public Safety for the state legislature, had several big findings:

• Teen use remained relatively flat: Using both state and national surveys, the report indicated "no significant change" among teens and high school students for past-month marijuana use.
• Adult use went up: "[T]he current prevalence rates for marijuana usage in the past 30 days have increased significantly for young adults (18 to 25 years old), from 21% in 2006 (pre‐commercialization) to 31% in 2014 (post‐commercialization). Reported current marijuana use by adults (26 years or older) increased significantly, from 5% in 2006 to 12% in 2014."
• DUI citations for marijuana were close to flat: "Traffic safety data is limited, but the Colorado State Patrol (CSP) found that the number of summons issued for Driving Under the Influence in which marijuana or marijuana‐in‐combination with other drugs decreased 1% between 2014 and 2015 (674 to 665)."
• Marijuana calls to poison control centers went up, from 44 in 2006 to 227 in 2015. And hospitalizations for possible marijuana exposures, diagnoses, or billing codes increased, from 803 per 100,000 between 2001 and 2009 to 2,413 per 100,000 between 2014 and June 2015. (One caveat: Marijuana overdoses cause mental anguish and severe anxiety, but they are not deadly.)
• Tax revenue is trending up: "Total revenue from taxes, licenses, and fees increased from $76,152,468 in 2014 to $135,100,465 in 2015 (+77%). Excise tax revenue dedicated to school capital construction assistance was $35,060,590 in 2015."
• Marijuana arrests dropped: "The total number of marijuana arrests decreased by 46% between 2012 and 2014, from 12,894 to 7,004." Although racial disparities remained: "The number of marijuana arrests decreased by 51% for Whites, 33% for Hispanics, and 25% for African‐Americans. The marijuana arrest rate for African‐Americans (348 per 100,000) was almost triple that of Whites (123 per 100,000) in 2014."

So some good and some bad. Teen use was flat, but adult use was up. There wasn't a spike in DUIs for marijuana, but there was an increase in marijuana-related calls and visits to poison centers and hospitals. And tax revenue went up while marijuana arrests dramatically fell, although racial disparities within those arrests remain.

There is reason for caution in interpreting the numbers, the report noted: "The decreasing social stigma regarding marijuana use could lead individuals to be more likely to report use on surveys and to health workers in emergency departments and poison control centers, making marijuana use appear to increase when perhaps it has not."

But there's also reason to believe the reported figures are conservative, since the report largely looked at data through 2014. That's still early in legalization — even to this day, for-profit companies haven't started to really mass-produce and mass-market their product, which could lead to more access and use. So it's possible that marijuana use and the risks associated with it will go up in the future.

Still, even if it's true that legalization led to more adult use and overdoses, that doesn't necessarily mean it was a mistake. Legalization's pros may still outweigh its cons.

Marijuana legalization is a balancing act

Even if legalization increases levels of pot use, it's unclear just how damaging that would be for society. Yet the downsides to not legalizing are definitely big — including more arrests each year over a comparatively mild drug, and more drug-related violence around the world.

In the US, hundreds of thousands of people are arrested for pot possession each year, ripping communities and families apart as people are thrown in jail or prison. There are enormous racial disparities in these arrests, with black people 3.7 times as likely to be arrested for marijuana possession as their white counterparts despite being only 1.3 times as likely to use the drug. And even a simple arrest can put a stain on someone's criminal record, making it harder to find a job or housing.

Around the world, drug cartels and gangs use profits from marijuana shipped to the US to maintain their stranglehold over trafficking routes, particularly through Latin America. Marijuana sales to the US make up a significant chunk of drug cartels' drug export revenue: as much as 20 to 30 percent, according to previous estimates from the Mexican Institute of Competitiveness (2012) and the RAND Corporation (2010).

This gives criminal groups more money to carry out violent trafficking operations in much of Latin America, which contribute to the killing and kidnapping of tens of thousands of people each year, and have spawned horrifying stories of cartels beheading and torturing people. And some of that violence occurs in the US, where gangs fight over turf to position themselves to sell illegal drugs.

Full legalization directly addresses the problems caused by prohibition. It cuts arrests for marijuana use. And it shifts sales from the black market to the gray market, where people sell legal pot under the table, as well as to the legal market — weakening or even eliminating a major source of revenue for drug cartels and gangs, leaving them less able to continue funding their violent acts.

Of course, all of this comes with the possibility that more people will abuse marijuana. But marijuana is a relatively mild drug: Studies show it's much less likely to cause accidents than more dangerous drugs like alcohol, and there's little evidence that pot causes severe health problems. So even if cannabis use goes up, it may not make the world much worse.

There are also ways to legalize that would reduce the risks. For example, a report by the RAND Corporation found that states could reduce access and increase prices by allowing only home growing and nonprofit sales, or having state governments directly manage sales like they do under state monopolies of alcohol sales. With these policies, states could minimize the harms of legalization and cut the downsides of prohibition.

All that said, America is still pretty early in its legalization experiment. Whether the benefits ultimately outweigh the downsides will take a few more years — or perhaps decades — to know for sure.