How Much Weed Is in a Joint? Pot Experts Have a New Estimate
How much marijuana is in a typical joint? Believe it or not, the question has perplexed experts for years. A new study claims to have an accurate estimate based on federal arrest data, and it’s less than regular users think.
Arriving at a trustworthy estimate is important for many reasons, including informing policy makers, law enforcement officials, health care providers and researchers.
Casual and scientific analyses have yielded a wide range of guesses as to the average contents of a marijuana cigarette, whether purchased or prepared at home.
At least one study placed the typical weight at 0.66 grams. The federal government has said it is closer to 0.43 grams.
The estimates from pot smokers are, shall we say, higher: Roughly one in four people responding to an informal poll last year by High Times, the cannabis magazine, said a typical joint contained one gram of marijuana. But nearly as many said it contained half that amount. Perhaps it depends how you roll.
The actual average may be much less. The new study, an analysis of federal drug arrest data published in the journal Drug and Alcohol Dependence, found the average amount of weed in a joint to be much smaller than those estimates: just 0.32 grams.
Such estimates about more than better understanding a high. Many users report marijuana consumption in terms of joints smoked, a statistic that is useless to researchers, authorities or policy makers without an accurate approximation of what that means.
“In order to get good projections, you need to be able to turn those answers — ‘I’ve had one joint in the last 30 days’ — into a quantity,” said Greg Ridgeway, a professor of criminology and statistics at the University of Pennsylvania who helped write the study with Beau Kilmer, a director of the RAND Drug Policy Research Center.
“These estimates can be incorporated into drug policy discussions,” the two researchers wrote, “to produce better understanding about illicit marijuana markets, the size of potential legalized marijuana markets, and health and behavior outcomes.”
Their estimate is based on marijuana purchase data collected from interviews with people who were arrested from 2000 to 2003 and from 2007 to 2010 under a Department of Justice program. While the answers came in many forms, Dr. Ridgeway and Dr. Kilmer focused on the more than 10,000 responses in which marijuana was measured in grams, ounces or joints.
The average price per gram, they found, was $6.81; the average joint was $3.50.
They couldn’t stop there. Although dividing the joint price by the gram price yields a rough estimate of a joint’s weight — about half a gram — it ignores how prices vary by location, time and quantity.
Those factors can significantly influence the estimates. Bulk discounts, in particular, modulate price. For example, the average price per gram jumps to $9.30 if the analysis is limited to purchases of five grams or less.
“When people buy an ounce of marijuana, they get a real volume discount,” Dr. Ridgeway said.
To account for those variations, the researchers applied a mathematical drug pricing model to the data, yielding their answer of 0.32 grams in the average joint.
Dr. Kilmer and Dr. Ridgeway acknowledge that their estimate is imperfect. It reflects just one population of marijuana consumer — people who have been arrested — and only in a smattering of counties across the United States.
But it is a convincing measurement nonetheless. Indeed, in 2015 a global drug survey conducted by academics found that most users get about three joints from a single gram of marijuana, or roughly 0.33 grams per joint.
Of course, weight is just a piece of the puzzle. Tetrahydrocannabinol, or THC, the chemical that produces the main psychoactive effects of marijuana, matters. And, like weight, THC content fluctuates, too: In a 2014 report, the White House Office of National Drug Control Policy estimated that marijuana’s average THC content rose from roughly 5 percent in 2000 to 8 percent in 2010.
Data from drug-related arrests offered a new insight into a matter critical for marijuana research and drug policy.
October 3, 2013 • 5 minute read
Mapping Cannabis Prices: An Interactive Visualization of Marijuana Sales
During a recent walk through the Tenderloin in San Francisco, a man asked me if I wanted to “trade a joint for a cigarette.”
This struck me as an odd proposition. Sure, California has no shortage of marijuana—there’s an entire Wikipedia article about cannabis in California, after all—but is it so prevalent that it’s cheaper than cigarettes? A pack of 20 cigarettes costs a little under $7 in California, or around 35 cents a cigarette. Could a joint cost so little?
Mapping the Price of Weed
For obvious reasons, collecting data on marijuana prices isn’t straightforward. Rather than relying on rigorously collected yet sparsely populated datasets like those collected through academic case studies, I instead turned to the biggest database of marijuana sales on the web: www.priceofweed.com. PriceOfWeed.com allows users to anonymously log marijuana purchases, inputting how much they bought, of what quality, at what price, and in what location. By scraping the website for all U.S. transactions from the start of 2012 through October 2, 2013, I was able to collect a dataset of nearly 130,000 individual sales. Though there are clear problems with user-inputted data—especially with regards to illegal substances—the size of the dataset likely smooths out a good bit of the noise and misreporting.
All 130,000 sales can be visualized, manipulated, and filtered in the interactive graphic below. Simply drag over selections in the bar charts to filter data, and see how average prices change by state.
A Joint for a Cigarette?
As the graphic shows, by national standards, marijuana is quite cheap in California. At an average price of $229 an ounce, a joint — which typically contains about 0.5 grams, or 0.018 ounces, of marijuana — costs about $4. While that’s cheaper than the average nationwide price of $5, it’s considerably more than a 35-cent cigarette.
But I was in the Tenderloin—maybe I was being offered a lousy joint. That’s not sufficient either: Low-quality marijuana in California costs an average of $206 dollars an ounce, or $3.60 a joint. (Interestingly, unlike above, this is higher than the national average. This perhaps suggests that Californians expect higher quality marijuana than most Americans, and judge what would be considered good marijuana elsewhere as poor.)
If low-quality marijuana doesn’t explain the proposed deal, maybe I’m not giving the Tenderloin enough credit. Maybe the man purchased his joints elsewhere in the state, and was a cunning arbitrageur taking advantage of market inefficiencies.
That’s possible — among cities with at least 20 sales, 21 of the 30 cheapest are in California. This includes the cheapest city in the country — Madera, at $129 an ounce. Still, even at that price, a joint would cost about $2.30.
What if he was arbitraging low-quality marijuana? The cheapest low-quality marijuana in the country comes from Bakersfield, CA. At an average price of $75 an ounce, however, Bakersfield’s joints cost $1.35—still four times the cost of a cigarette.
But even that may not be going far enough. As a dealer, he could be getting volume discounts, if they exist. Because distributors who hold large quantities of marijuana are subject to harsher penalties, such discounts may not apply to illegal drug trade.
Despite this, it turns out that drug markets still behave more or less normally. In the 1,162 cities for which there are at least 20 transactions, average per ounce prices are about $50 cheaper for every additional eighth of an ounce purchased. Evidently, the efforts and risks required to find more buyers are more costly than the danger of holding additional inventory.
This leaves me with two possible conclusions. The man was either a brilliant businessman, offering me low-quality weed purchased in large quantities, and imported from Bakersfield, or it was a joint full of oregano. But wait…
See how we mapped Cannabis prices across the United States and turned the data into interactive visualizations. How much does a joint cost? Let's find out.