The retail price of marijuana is sliding nationwide as regulations replace cannabis prohibition, and the “risk premium” for the product goes down.

This week, researchers analyzing Washington found dramatic price slides after an initial price spike when the state’s legal cannabis program began in late 2014. And Colorado’s prices have slid even further, Washington Post notes.

While some medical marijuana activists in California falsely claim that legalization will raise prices through corporatization — the precise opposite is happening, thanks to the laws of supply and demand. Alcohol costs tripled under prohibition and quality control plummeted, researchers note.

Californians pay up to $20 per gram for marijuana in dispensaries. In Washington, prices per gram have slipped from a post-legalization high of $25 per gram, to less than $10 per gram now.

In Colorado the average price per retail gram was down to $5.77 on 4/20, off an average of $8.86 for the same period in 2014, BDS Analytics reports. Cannabis’ commodity cost could be $2 per gram, researchers estimate.

Black market dealers are quitting the game, Denver Westword reports.

“My dispensaries were charging $55 an eighth before tax when we first opened in 2014, and now we charge $25,” a Colorado operator told Westword. “But in states like Massachusetts, the prices are still high because consumers don’t have as many options, or the buyer pool is limited because of medical marijuana restrictions. Here, we have availability.”

California voters will have a chance to legalize cannabis this fall, but face opposition from vested interests including a mix of law enforcement, as well as some medical cannabis industry members and activists. The official position of the California Growers Association is that legalization’s failure this year “would not be considered a failure.”

California’s robust and newly regulated medical marijuana is already exerting downward pressure on the price of pot. While boutique strains still fetch $60 per eighth in California, low-grade cannabis is given away as a loss leader for new patients.

Still, research shows that cannabis law liberalization does not result in an increase of teen use or availability; weed’s been widely available to teens since the ‘70s, researchers note