On October 17, 2018, Canada became the first G7 nation to fully legalize recreational cannabis. Cue the speculators. As a massive, formerly black market transforms into an above-board one, companies from around the globe in a range of disparate industries—agriculture, yes, but also tobacco, beer, software, and even fashion and design—aim to cash in.

But no one knows exactly how large this market will be. Both immediately and in the coming years, attitudes about marijuana in Canada inevitably will change. Meanwhile, the unknowns are impacting everything from share prices to government policies. As jurisdictions in the U.S. and around the world ponder changing their own cannabis laws, they’re watching to see how the numbers shake down in Canada.

The Numbers Game

According to Statistics Canada, 4.9 million Canadians used cannabis in 2017, spending $5.7 billion Canadian dollars on pot, 90% of that on the illegal market. For context, Canada has a population of 37.1 million, which is about one-tenth of that of the U.S. It’s actually close in size, population wise, to California, which has 39.7 million residents.

Cannabis has been legal in Canada for medical purposes since 2001. It requires a doctor’s approval and people must buy direct from producers licensed by the federal government. That industry was worth $400 million CAD in 2017, in contrast to California’s $3 billion market the same year.

In the wake of full legalization, estimates of the market’s potential vary. The Canadian bank CIBC predicts the market will grow to $6.8 billion CAD by 2020, with Canadians using 800,000 kilograms (1.7 million pounds) a year. Provincial governments, it speculates, will take in $3 billion CAD in earned profits and taxes.

On the other hand, Deloitte predicts the recreational market alone could reach $8.7 billion CAD a year, with a $22.6 billion CAD “overall economic impact” (that includes businesses that supply things associated with growing cannabis, like grow lamps and fertilizer, manufacturers of vaporizers, and companies making things like cannabis beer).

These predictions came out prior to legalization. Experts may start tweaking their numbers: in the first 24 hours of legal sales, Ontario’s online store had 100,000 orders. Most provinces’ cannabis sales portals either sold out of most strains or crashed — or both — on October 17.

Troubles with Estimates

In the 2014 book What America’s Users Spend on Illegal Drugs, 2000-2010, the authors outline the challenges in tallying the drug market, which they call “an inevitable consequence of trying to measure sales of something sold in hidden markets or consumption behavior that is both illegal and dominated by a relatively small number of heavy users.”

To make a market estimation, the authors say, one must assess the supply side by looking at land under cultivation via aerial images and interviewing farmers, then extrapolate yields. How much of what’s grown will actually make it onto the market? Then, add in data from drug seizures, which accounts for but a fraction of the drugs out there.

That gets balanced by information about demand, for which researchers have no choice but to look to notoriously unreliable surveys and intake questionnaires. When asked about cannabis, people will claim not to use it, but will “indicate later in the survey that they have used blunts, a particular form of marijuana use.” Most researchers round up by a third when estimating true cannabis use, and even this method may be overly conservative.

Meanwhile, many estimates about what will happen in Canada look to U.S. jurisdictions like Colorado, which legalized recreational pot in 2012. The state, which has a population of 5.6 million, sold $1.5 billion worth of cannabis in 2017, more than doubling its market in just three years. However, it’s difficult to compare a state surrounded by others where it’s illegal—border towns in Colorado have unusually high sales—to Canada, which will have nationwide legality.

U.S. states where cannabis is legal are in certain ways like Holland, which allows for possession of 5 grams of marijuana, but adopts a policy of non-enforcement for up to 30 grams. It has done so since 1976. Amsterdam’s coffee shops are part of its allure for tourists, many of whom are keen to use cannabis legally and in public.

But when a whole country goes legal, it has unique effects. According to the journalist and renowned author Larry Collins’ 1999 Foreign Affairs article “Holland’s Half-Baked Drug Experiment,” legalization led to a huge attitude shift in the country. Not only did reported pot use soar by 200% among youth between 1984 and 1996, but people seeking help for cannabis addiction rose by 25% in 1997 alone. The country became the “drug capital of Europe,” Collins wrote, and a hotspot for distributing hard drugs like cocaine and heroin to other countries. Holland also provided a (somewhat) safe haven for makers of synthetic drugs.

Numbers Matter

The speculative math of estimating the cannabis market means no one knows the true value of cannabis companies. Leading up to legalization in Canada, market valuations and acquisition deals kept breaking new records.

In mid September, Tilray Inc. of Nanaimo, British Columbia, became the most valuable cannabis company in the world at $14 billion. It’s not the largest cannabis company in Canada, but its shares are listed on the Nasdaq, which gives it access to U.S. investors, while its competitors are listed on Canadian stock exchanges.

Then there was the colossal deal a few months ago that saw Constellation Brands Inc., of New York, take a majority stake in Canopy Growth Corp. in Ontario, ultimately spending $5 billion CAD to do so. Canopy’s shares shot up 83% around the time the acquisition was announced.

Amid these deals, industry observers warn of the possibility of a cannabis bubble, one that could lead to a dot com-style bust if these companies get too heavily valued without the sales to back things up. Indeed, most cannabis stocks dipped around legalization. Sector crashes, as we know, impact the whole economy, even on a global scale. But governments have to crunch cannabis use numbers so they’re ready for new social costs. While legalization lessens the pressure on the legal system—and actually makes traffic fatalities drop by 8-11% in the first year, according to a 2013 report—it does trigger other costs.

Canada has a public healthcare system. In the article “For And Against: Cannabis Control: Costs Outweigh The Benefits,” the “Against” author Colin Drummond notes that the World Health Organization stated in a 1997 report smoking cannabis is twice as carcinogenic as tobacco—and cancers as a result of pot appear earlier. Other reports dispute this, meanwhile, plus using a vaporizer seems to dramatically reduce such health risks. Pot use in any form can trigger schizophrenia and other psychotic disorders and can cause dependency, increasing the use of drug treatment clinics.

The hard-to-pin down cannabis numbers in Canada are turning the country into the Wild North, with new players coming into the market all the time, and money being thrown around. But the wait will soon be over. Cannabis is legal and the provinces are selling pot directly to consumers. We’ll know soon enough how many people are getting high and who among them will need government services as a result. And who gets wildly rich off this new market.