Marijuana legalization opponents have repeatedly warned that cannabis dispensaries will breed crime, lead adolescents to seek out cannabis, and worsen public health overall. But several years of post-legalization data from numerous states shows that the evidence just doesn't bear out those arguments.

In fact, what researchers have found is that dispensaries — and the access to legal cannabis that they offer — actually benefit communities across the country. If that sounds counterintuitive, here's an overview of studies that explore the impact of your local pot shop.

Law enforcement can focus on higher priorities.

This one involves some simple math. When you subtract a crime like marijuana possession from the law enforcement equation, police resources that might have gone toward busting someone over a loose joint can be redistributed, freeing up officers to pursue more serious crimes.

That appears to be the experience in Colorado and Washington state, according to one study published July 2018 in the journal Police Quarterly. In the years since the states fully legalized cannabis, police clearance rates — or the number of crimes that resulted in an arrest compared with the total number of reported crimes — increased for both violent and property crimes. The same couldn't be said of the country as a whole.

“[I]n the absence of other compelling explanations, the current evidence suggests that legalization produced some demonstrable and persistent benefit in clearance rates, benefits we believe are associated with the marijuana legalization proponents' prediction that legalization would positively influence police performance,” the study authors wrote.

Dispensaries take a bite out of the opioid epidemic.

This topic has been of particular interest to researchers and public health experts: can legalizing marijuana combat the country's overwhelming opioid problem? Study after study after study has indicated that the answer is “yes.”

What's become increasingly clear is that providing legal access to a plant that's known to treat pain can divert some people from using opioids. Because prescription opioids are strongly addictive, there's a risk that people who take them will eventually turn to harder and more deadly drugs such as heroin. Cannabis represents a safer alternative, and some people take advantage of that when dispensaries open up shop.

That's likely why studies have shown that people take fewer opioid prescriptions and die from opioid overdoses less often in legal marijuana states compared with their non-legal neighbors. In November 2018, researchers looked at local data and demonstrated just how important the “access” element is, revealing that counties where dispensaries operated experienced 6 to 8 percent less opioid overdose deaths overall and 10 percent fewer heroin overdose deaths.

“Importantly, these effects are limited to counties where dispensaries opened and do not apply to non-dispensary counties in states with that have legalized medical cannabis,” wrote lead researcher Julio Garin of the Robert Day School of Economics and Finance at Claremont McKenna College in Claremont, California.

Regulation works. Young people aren't flocking to pot shops.

For good reason, both pro- and anti-legalization folks are interested in preventing underage marijuana consumption. But where the groups disagree is on the effects of dispensaries on youth consumption trends, and the research has demonstrated that the mere presence of these shops is not driving teens to use more cannabis. That's by design, too — it's why dispensaries require photo ID, unlike illicit dealers.

There have been a number of recent studies exploring this trend. For example, a study published in the Journal of Adolescent Health found no connection between the number of medical marijuana dispensaries within 3 miles of a school and higher rates of adolescent cannabis use.

“We reported null associations of the proximity and density of medical marijuana dispensaries in school neighborhoods with adolescents' use,” according to the study's lead researcher Yuyan Shi of the Department of Family Medicine and Public Health at the University of San Diego.

While states with legal marijuana do generally have higher rates of youth consumption, a survey of 4,000 teens across the U.S. demonstrated that legalization wasn't behind that; rather, the trend seems to be “pre-established” before the end of prohibition, according to the study published in July 2018 in Drug and Alcohol Review.

And if you still need convincing, a meta-analysis of 55 studies came to the same conclusion. Put simply, the existing scientific literature suggests “that passage of [medical marijuana laws] has not increased cannabis use among teenagers during the periods after their passage that has been studied to date.”

No, crime doesn't spike when dispensaries move in.

At the same time that legalization seems to empower police to take on other crimes, the argument that dispensaries themselves attract crime is unsupported by evidence. In general, studies have determined that legalizing cannabis simply doesn't have an impact on crime rates at all. But at least one recent study that examined county-level data in California did turn up results indicating that dispensaries are associated with lower property crimes.

Counties that allowed dispensaries to operate experienced a "5.1 percent statistically significant drop in reported property offenses during the years in which counties allowed for dispensaries," researchers at the think tank Rand Corp. wrote.

Meanwhile, a study published in March 2018 in the journal Preventive Medicine did point out that violent and property crimes significantly increase around shops that sell alcohol and tobacco, but not near medical marijuana dispensaries.

Oh, and opening dispensaries actually increases housing prices.

Contrary to the notion that pot shops devalue neighborhoods, a new set of studies revealed that housing prices for new homes increase by almost 8 percent after a dispensary opens within a quarter-mile, or 402.3 meters. In fact, the effect is roughly the same as when new grocery stores are built.

“Our results suggest that despite potential costs, legalization is capitalized as a net benefit in housing price.”

Similarly, an analysis found that Airbnb rental costs decrease by about 3 percent on average in Amsterdam if a cannabis coffeeshop closes within 250 meters of the lodging.