A "bud tender" at the High Times 420 SoCal Cannabis Cup in San Bernardino, CaliforniaRichard Vogel / AP

Recreational marijuana will no longer be a priority for Canada’s criminal-justice system. This week the Senate passed legislation that will make the country the second in the world to strictly regulate weed—but technically legalize it—beginning in October. The first was Uruguay, so Canada is the first major economy, and an experimental model for the rest of the world that will inform policy for decades to come.

Canada’s approach offers much promise from a health perspective. “This is the most well deliberated and crafted legalization legislation in the world,” says Andrew Freedman, who led the creation of a regulatory framework for Colorado’s marijuana legalization. “Canada approached the creation of the production, management, and distribution with a public-health lens. I’m excited to see what happens with health outcomes compared to Colorado, where it really is a more capitalist model.”

From a public-health perspective, the ideal marijuana policy would maximize benefits to the criminal-justice system while minimizing social and health effects of abuse and misuse. Indeed the move comes in the same week that researchers at Columbia University’s Mailman School of Public Health raised concern that marijuana use is becoming more common in the United States “in the context of increasingly permissive cannabis legislation, attitudes, and lower risk perception.”

Not long after leaving Harvard Law School, Freedman was cast into an unprecedented role as the first-ever governor's director of marijuana coordination (sometimes referred to as the “marijuana czar”). Having been thrown head-first into the job, he now runs a consulting company working with other states on policy implementation—in part to avoid repeating his mistakes in Colorado. Freedman was excited by the fact that the goal in Canada is “to meet demand for cannabis, but the approach isn’t as commercial or profit-driven as what you’d generally see in the U.S.”

Details of the regulatory framework remain to be seen, The New York Times reports, but a few elements stand out as health safeguards: There will be “strict limits” on advertising, and marijuana will “likely be sold in uniform packages that carry health warnings as their only decoration,” and candies and other edibles will be banned.

This level of regulation has been criticized by some marijuana advocates, and it would have seemed excessive to me when I first reported on marijuana legalization in Colorado in 2014. I didn’t expect to hear many health-related objections—especially as compared to other substances that account for so much more harm. Indeed the sheriff of Pitkin County, Joe DiSalvo, told me that not much had changed in the months since dispensaries started opening. He pushed back against my obligatory questions about whether Aspen had been overrun by marijuana and “dope fiends.”

Later that night at a bar down the street from his office, though, I found myself on stage moderating a much heavier discussion with two affable young men who turned out to be very concerned about legalization. They made a passionate case that the state wasn’t ready to regulate such an industry, and that a public-health crisis loomed—once what they called “Big Marijuana” started marketing and profiting in the ways of so many other politically influential entities.

I felt irresponsible as a doctor for not having considered how slippery the slope could become in the longer term. Their argument, essentially: The streets were quiet now, but in short order, Big Marijuana could be the next Big Tobacco or Big Alcohol or Big Soda. The forces of capitalism would see the streets flooded with weed and weed-laced products, ever more potent and ever more desirable. Marketing messages would teach us that daily marijuana use was good or even necessary. Once the industry got the money and lobbying power it needed, regulations would grow more and more relaxed. As regulation and enforcement waned, the few storefronts that didn’t end up peddling THC in some form—edible, smokable, vape-able, topical, insertable—might feature vending machines or ads for weed. There could be enormous neon billboards with cartoon characters selling weed candy at amusement parks. And it won’t just be about the kids. People in grocery-store checkout lines who had no prior interest in weed would opt to pick up a THC-infused granola bar, and then they would start buying one every day. Politicians who attempted to rein in the chaos would be pilloried and ousted by Big Marijuana lobbyists.

Though there is precedent for such concerns, from fossil fuels to health insurance, this has yet to happen with marijuana. The rollout in Colorado was far from perfect, but many retroactive regulations were able to be implemented to address ongoing issues like the use of home-growth practices and pesticides, selling and transporting across state lines, driving while high, driving while not-high-but-also-not-entirely-sober, standardization of dosing, and labeling. In 2014 I purchased THC-laden candy that looked identical to Sour Patch Kids, and the recommended dose was half of one piece of the candy. The potential for confusion and harm there was obvious.

By Freedman and others’ admission, the Colorado rollout was undertaken without an ideal evidence base, and without precedent to inform plans for all of the complications that would arise. It was and remains an experiment, and Canada’s will be as well—inevitably imperfect, but promising because the country is better positioned to stay in control of the substance than the United States.

While Freedman believes U.S. regulators have not become beholden to industry influence in the way of the most dystopian forecasts, the possibility should be in the minds of public-health advocates and policy makers. “We’re right in the middle of that battle,” he told me. “It’s not a fait accompli. There are plenty of things that communities can do to come together to create countervailing forces against overreach by the industry. There’s plenty that enlightened industry itself can do to keep bad actors at bay.”

Increasing the number of occasional consumers isn’t necessarily a health concern—especially if consuming marijuana replaces drinking alcohol or using other drugs. But there is concern about perverse incentives in the industry, as have been seen over the decades with tobacco and alcohol, where roughly 80 percent of the product goes to 20 percent of the users. For these people, overuse is somewhere between a concern and a serious problem.

Right now the U.S. marijuana industry is a convergence of markets, where the legal industry is still mostly siphoning business from the illegal industry. But once the black market is tapped, there can be incentive to grow that 20 percent. It’s most profitable to cultivate lifelong, heavy users. In the cases of tobacco and alcohol, the strategies were to get people to use more or to start using earlier.

So the critical balance of effective marijuana policy is to incentivize producers to make enough to meet demand, but not to substantially grow the market. In Uruguay, where marijuana went on sale at some pharmacies last year, the government-controlled supply chain has not met demand, and a national shortage has kept the black market in business. In Canada, the supply will be privatized but regulated by the federal government, and the states will be involved in retail to various degrees. Academically, this will allow comparisons between provinces that impose tighter regulations on advertising and distribution—doing more to minimize profit incentives than others. The effects on demand, crime, and health outcomes will be cited in future policies around the world, on an ever more informed march away from prohibition.

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