The study looked at data from nearly 1,500 census tracts in the state from 2014 through 2017. The researchers found that in low socioeconomic neighborhoods, there were higher rates of cannabis processors and retailers.
The researchers hope the research will be valuable for state policymakers. The researchers created an interactive graphic, which can be found here.
"Our main aim was really to put it out there and let policymakers think about it in a way that maybe they didn't think about it before," says Ofer Amram, one of the authors of the study.
Low-income neighborhoods saw a 258 percent increase in retailer density from 2014-2017 compared to higher-income neighborhoods, according to the study. Those neighborhoods also saw a 159 percent increase in producer density and a 120 percent increase in processor density.
The study didn't examine specifically why pot shops are located in poorer neighborhoods. But Solmaz Amiri, the lead author of the study, says it's plausible that land is cheaper in those neighborhoods and that the more affluent neighborhoods have more resistance to having weed shops there.
This isn't unique to Washington. In Colorado, the Denver Post found, cannabis businesses proliferate in poorer neighborhoods.
Amiri says they conducted the study to learn more about how cannabis impacts communities. This, she says, is the first step.
"We are going to follow the trend and any kind of health outcomes that people may have in the state over time, and related to location of [cannabis] businesses," she says, "to see if they really are impacting these lower socioeconomic communities."
Of course, she says, it's possible that the location of the businesses doesn't correlate with the communities that use cannabis. People may be more than happy to drive out of their way to a cannabis retail shop, she says.
The researchers say they have shared the study with the Washington State Liquor and Cannabis Board. The goal is to provide state regulators and lawmakers with a better understanding of cannabis legalization and its ramifications.