RAND’s study, “Before the Grand Opening,” aims to take a snapshot of pot use here on the eve of legal sales. It found that half of the marijuana used in the state is consumed in the state’s three most populous counties. King County, which includes Seattle, accounts for about 30 percent, while Pierce to the south and Snohomish to the north account for about 11 percent each.
The study drew on national, government-funded surveys, but the researchers also conducted their own online survey of marijuana users to address a gap in the national research: How much marijuana do people use when they use it, especially because pot is often shared? One of the primary national surveys on drug use stopped asking people how many joints they smoked nearly 20 years ago, noted RAND study author Beau Kilmer.
Especially important is figuring out how much pot is smoked by consumers who use it more than 21 days per month, Kilmer said. That relatively small segment of the market accounts for about 80 percent of all marijuana used, according to earlier research, and there’s still a lot to learn about those users, he said.
“If you can get a good idea about what those heavy users use, you can get a pretty good idea about the size of the market,” he said.
The team determined an online survey was the best way on a relatively tight deadline to get an idea of how much pot people use, despite limitations such as the self-selection of participants in the survey and the possibility of insincere respondents — “scoundrels,” the authors called them — trying to throw off the results. Ultimately, the authors developed ways to try to flag such responses.
The pot users were shown pictures depicting a gram or half-gram of marijuana next to a credit card and a coin for scale — an unusual idea aimed at improving the accuracy of their responses about how much they use. Nearly 64 percent of the 2,783 respondents from Washington state reported using pot at least 21 days per month, typically 1.3 to 1.9 grams per day on each day that they used, the report said.
A gram of marijuana often sells for $10 to $12 in Washington.