Pot use among Washington state teenagers fell following legalization, according to a new study published today.

Researchers with the RAND Corporation analyzed data from a statewide survey of high school students and found that teen cannabis use fell during 2014 and 2016 as compared to the pre-legalization years of 2010 and 2012. Pot use by eighth graders feel from 9.8 percent to 7.3 percent and 10th grade pot use fell from 19.8 percent to 17.8 percent. There was no reported change in high school seniors.

This new RAND paper goes against a previous study published last year in the same journal, JAMA Pediatrics, which found that pot use increased by 2 percent and 4.1 percent among eighth and 10th graders after legalization. The RAND researchers said that particular study used a nationwide dataset that's less capable of analyzing teen pot use specific to Washington state.

Rosalie Liccardo Pacula, a co-author of the study, said in a press release that the new results show the need to use multiple sets of data when analyzing public health questions.

“This work underscores the importance of understanding who is being captured in each data set so we can better understand how representative the sample is when trying to draw policy conclusions from the analysis," Pacula said.

The new RAND Corporation study confirms an earlier finding from the Washington Legislature's think tank, which used data from the same survey and also found that teen use of cannabis had fallen.