A new poll found that 91% of adults who have consumed cannabis have done so for health and/or wellness purposes

Ten years ago Colorado became the first state in the U.S. to fully legalize the recreational use of cannabis. Many other states followed, and several others already had sufficiently lax medical marijuana legislation, that now an estimated 40% of American adults can legally buy cannabis. Musicians, actors and sports stars have quickly jumped into the market with their own brands of weed, hoping to lure people who want to get high with a high-end product. Some of these—Willie NelsonSnoop DoggSeth Rogen—are unsurprising. Others are less likely weedpreneurs, including Bella Thorne, Jaleel White—the actor who played Steve Urkel in Family Matters—and former NBA star Al Harrington. The newly legal industry was predicted to be a multibillion dollar business and a big tax revenue win for the states.

But it hasn’t been that simple, according to the authors of the new book Can Legal Weed Win?: The Blunt Realities of Cannabis Economics. The two economists from the University of California, Davis’s Department of Agricultural and Resource Economics found that the future of the legal cannabis business, hampered by regulation, competition and standard agricultural issues, is a bit hazy. TIME spoke to the authors, Daniel Sumner—who is also a former assistant secretary of economics at the U.S. Department of Agriculture—and Robin Goldstein, who is also the author of a controversial bestselling guide to wine, The Wine Trials.

This interview has been edited and condensed for clarity.

The Economics of Legal Weed Don’t Work

Not quite half of American adults can now buy weed legally. How’s business going?

Daniel Sumner: It’s been tough. There’s still a whole lot of illegal weed out there available to that same group of consumers, and most of them choose the illegal product because it’s half the price. Also, they have been consuming the product for the last 20 to 40 years; they’ve been dealing with this guy who knows a guy and they’re reasonably happy with the product.

Read the complete interview at: https://time.com/6184704/legal-marijuana-economics/