Marijuana Plantation
Cpl Ryan Belgrave with the Canadian Army's 1st Battalion, The Royal Canadian Regiment Battle Group, walks through a field of marijuana plants during a patrol near the village of Salavat, in the Panjway district west of Kandahar August 4, 2010. Reuters/Bob Strong

Researchers have recently estimated that an average marijuana joint contains only 0.32 grams (0.01 ounces) of cannabis and that is much lower than some previous estimates. While it may seem odd to try and ascertain the amount of cannabis in a joint, the researchers believe major policy decisions depend on the amount.

The new study, published in the journal Drug and Alcohol Dependence, suggests that the number “0.32 grams” of marijuana in a joint is critical in estimating how much cannabis is being consumed nationwide. Moreover, it will also help in finding out how much states may expect in revenue after cannabis legalisation. It is also important in find out how much drug-trafficking organizations are putting on the market.

There has been no consensus on the amount of cannabis in a joint up to now. Previous studies have provided various numbers such as 0.43 grams (0.02 ounces) and 0.75 grams (0.03 ounces). Study co-author Greg Ridgeway, an associate professor of criminology and statistics at the University of Pennsylvania, said that the new study findings are based on data from more than 10,000 cannabis purchases over 11 years.

A survey of people who were arrested and interviewed on their drug purchases and substance use in the US provided the data for the new study. The researchers found out the average grams of cannabis in each joint after the interviewees mentioned how much they paid for a certain number of joints.

Differences in marijuana prices in various areas were also considered along with price inflation over the years.

“My colleague and I used this dataset and an economic model that’s been used for about 30 years now to untangle weight and price, to estimate the average joint weight. That all boils down to about 0.3 grams, which is much less than previously thought,” Ridgeway said in a statement.

The researchers said that the study’s findings can be incorporated into drug policy discussions to have a better understanding of illicit cannabis markets, health and behaviour outcomes and size of the potential legalised marijuana markets.