Published on December 18, 2013 at 1:08 AM
The Washington state marijuana consumption estimates were compiled using information from the federal National Survey on Drug Use and Health, as well as a web-based survey of marijuana users in Washington state compiled by the research team. The online survey included novel approaches such as showing participants photos of marijuana to help them better report the actual quantity that they use.
"The federal National Survey on Drug Use and Health provides useful information about marijuana users, but it does not account for all of them," said Jonathan Caulkins, a study co-author and the Stever Professor of Operations Research and Public Policy at Carnegie Mellon University. "We devoted serious attention to this undercounting issue in the report."
The RAND report estimates marijuana consumption in each of Washington's 39 counties, showing that the state's three most-populous counties (King, Snohomish and Pierce) account for about half of all use.
Support for the study was provided by the state of Washington as part of a contract with BOTEC Analysis Corporation, which advised the state on technical issues related to implementation of legal marijuana in the state.
Voters in Washington approved Initiative 502 in November 2012 that legalized recreational use of marijuana for those aged 21 and older, and requires the state to regulate and tax a new marijuana market. Commercial marijuana stores and associated supply chains are scheduled to begin operating in 2014.
Source: RAND Corporation