VANCOUVER - It's a bounty that almost does grow on trees.

A new study has rung in British Columbians' pot purchases at about half a billion dollars each year, leading its pro-legalization researchers to argue current laws mean the province is missing an opportunity to harvest tax revenues.

Researchers from the University of British Columbia and Simon Fraser University have quantified the retail value of black market marijuana sold only to British Columbians for the first time, pegging its value at between $443 million and $564 million annually.

"What's important is to get a sense of how many people are using marijuana in B.C., and how much they're using, and how much that's worth," said Dan Werb, the study's lead author and co-founder of the International Centre for Science in Drug Policy. "That data drives policy."

The study comes as part of a growing campaign of health, legal and law experts to persuade politicians in B.C. to look at alternatives to the current system they argue fuels gang violence and does nothing to reduce drug use.

The campaign has gained momentum after Washington State and Colorado voted earlier this month to legalize, sell and tax marijuana, and the study's researchers are already watching lessons from the incoming implementation.

Using data from Health Canada and the Centre for Addictions Research of B.C., the researchers found the population of marijuana users to be about 366,000 and the retail cost to be about $7.50 per gram.

They used data about how often and how much is used in conjunction with those figures to determine the size of the illegal provincial market.

The paper doesn't specifically estimate tax revenues.

"But what it does is lay the groundwork and points to a few ways policy-makers could start looking at tax revenues," Werb said.

He cited government data from Washington State, which lays out the fiscal impact of the marijuana ballot initiative, and noted the population of weed users in B.C.'s neighbour to the south is estimated at 363,000 — a very similar number to B.C.

Initiative 502 puts in place a 25 per cent tax on pot sales, and the government anticipates that starting two years from implementation, the state will bring in tax and licensing revenues nearing half a billion each year.

The coalition contends that B.C., too, could rake in $2.5 billion over five years.

In Washington, 55 per cent of taxes will go to health care, 25 per cent to drug abuse treatment and medication, one per cent for cannabis-related research and the remainder will be general revenue.

"It would allow revenues that are currently being used towards the enforcement of cannabis laws be diverted perhaps towards the organized crime unit or other enforcement interventions that would target higher-level traffickers," Werb suggested of B.C.

Two economists at the University of British Columbia agree that millions in tax revenues would likely be generated from regulated pot sales, though they suggested caution be taken in estimating the enormity of the windfall.

Prof. Werner Antweiler said economic principles suggest that taking weed off the black market and into a regulated system would lower the overall price of the product — though not its demand — and therefore generate less.

But he also noted the 25 per cent tax created by Washington seems to be at the low-end of what he might expect to see applied to marijuana.

He said that in Canada, taxes on tobacco account for 81 per cent of the retail price — largely to account for high health-care costs associated with lung cancer, and because governments are trying to dissuade its purchase.

Putting a larger, so-called sin tax on marijuana would not tread new ground, added Prof. Kevin Milligan.

He said the result of the tax would be similar to what happens with environmental taxation, which is called a "double dividend."

"The point of the tax is you get less illegal activity, and some revenue you can do something with," he said. "It could potentially benefit B.C. taxpayers."

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  • Alaska

    Legalized for medical use. <a href="" target="_hplink">Flickr: alana sise</a>

  • Arizona

    Legalized for medical use. <a href="" target="_hplink">Flickr: Bill Ward's Brickpile</a>

  • California

    Legalized for medical use. <a href="" target="_hplink">Flickr: gerbache</a>

  • Colorado

    Also legalized possession by non-medical users. <a href="" target="_hplink">Flickr: dok1</a>

  • Connecticut

    Legalized for medical use.

  • District Of Columbia

    Legalized for medical use. <a href="" target="_hplink">Flickr: ~MVI~ (off to coron)</a>

  • Delaware

    Legalized for medical use. Flickr: <a href="">Doug Kerr</a>

  • Hawaii

    Legalized for medical use. <a href="" target="_hplink">Flickr: Ricymar Fine Art Photography</a>

  • Illinois

    Legalized for medical use.

  • Maine

    Legalized for medical use. <a href="" target="_hplink">Flickr: indywriter</a>

  • Maryland

    Legalized for medical use.

  • Massachusetts

    Passed ballot initiative for legalized medical marijuana in 2012.

  • Michigan

    Legalized for medical use. <a href="" target="_hplink">Flickr: ckay</a>

  • Montana

    Legalized for medical use. <a href="" target="_hplink">Flickr: csbarnhill</a>

  • Nevada

    Legalized for medical use. <a href="" target="_hplink">Flickr: http2007</a>

  • New Hampshire

    Legalized for medical use.

  • New Jersey

    Legalized for medical use. <a href="" target="_hplink">Flickr: psflannery</a>

  • New Mexico

    Legalized for medical use. <a href="" target="_hplink">Flickr: michaelwhitney</a>

  • Oregon

    Legalized for medical use. <a href="" target="_hplink">Flickr: digging90650</a>

  • Rhode Island

    Legalized for medical use. Also decriminalized possession of less than one ounce.

  • Vermont

    Legalized for medical use. <a href="" target="_hplink">Flickr: BryanAlexander</a>

  • Washington

    Legalized for medical use. Also legalized possession by non-medical users. <a href="" target="_hplink">Flickr: Rose Braverman</a>

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  • $13.7 Billion Saved On Prohibition Enforcement Costs

    The government would save an estimated $13.7 billion on prohibition enforcement costs and tax revenue by legalizing marijuana, <a href="" target="_hplink">according to a paper endorsed by 300 economists</a>.

  • $500 Million In Tax Revenue For Washington State

    It's estimated that Washington's legalization of marijuana could bring the state an<a href="" target="_hplink"> additional $500 million in tax revenue</a>, WPTV reports.

  • $60 Million Saved By Colorado Legalization

    Colorado's pot legalization legislation, Amendment 64, is estimated to create <a href="" target="_hplink">$60 million for the state in combined savings and additional tax revenue</a>, Colorado Springs Business Journal reports.

  • Legalization Could Reduce Marijuana Prices

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  • Huge Prison Cost Savings

    Inmates incarcerated on marijuana-related charges cost U.S. prisons $1 billion annually, according to a 2007 study, <a href="" target="_hplink">AlterNet reports</a>.

  • Marijuana Prohibition Costs Taxpayers $41.8 Billion A Year

    Including lost tax revenues, a 2007 study found that enforcing the marijuana prohibition costs tax payers $41.8 billion annually, <a href="" target="_hplink">Forbes</a> reports.

  • California Marijuana Crop Worth $14 Billion A Year

    Marijuana growers account for <a href=",8599,1884956,00.html" target="_hplink">$14 billion a year in sales in California</a>, making it the state's most valuable cash crop, TIME reports.

  • Illegal Marijuana A $36 Billion A Year Industry

    It's estimated that <a href="" target="_hplink">illegal marijuana is a $36 billion industry</a> in the U.S., MadameNoire reports.

  • Dispensary Ads Boost Newspapers' Revenue

    The <em>Sacramento News and Review</em> saw a big boost in ad revenue when it offered advertising space for more than 60 medical marijuana dispensaries, enabling the publication to hire three additional employees, <a href="" target="_hplink">according to News 10</a>.

  • Mendocino Zip Tie Program Raised $600,000

    Mendocino County, California's zip tie program aimed at regulating medical marijuana growing by charging permits for each plant raised <a href="" target="_hplink">$600,000 in revenue in for the Sheriff's department</a> in 2011.

  • Oakland Raised More Than $1 Million In Marijuana Tax Revenue

    The city of Oakland, California raised $1.3 million in tax revenue from medical marijuana dispensaries in 2011, 3 percent of the city's total business tax revenue, according to <a href="" target="_hplink"><em>The New York Times</em></a>.

  • Colorado Pulls In $5 Million From Pot Sales Tax

    In 2011, Colorado pulled in $5 milllion in sales taxes from medical marijuana businesses, <a href="" target="_hplink"><em>The New York Times</em></a> reports.

  • Legal Marijuana Could Be $100 Billion Industry

    Economist Stephen Easton estimated in 2010 that <a href="" target="_hplink">legal marijuana could be a $45 to $100 billion industry</a>, <em>Bloomberg Businessweek</em> reports.

  • Each weGrow Center Creates 75 Jobs

    When hydroponic marijuana growing supply chain weGrow opens a new store it <a href="" target="_hplink">creates an estimated 75 jobs</a> indirectly, according to AZBusiness Magazine.