How much legal pot will the Washington State market demand? This is the main question the state will assign to its new cannabis consultant, who will advise the liquor board on matters of cannabis production, processing, and testing.

Curious and (coincidentally) legally high, I wondered how smart people might approach this question. The obvious solution to me—hire a polling company—was also obvious to people who weren't high. "That's funny, we're bidding on that contract," responded Ian Stewart from EMC Research before politely declining my request for an interview. He imagined every local polling firm was also bidding on the contract.

Before Initiative 502 passed in November, the state's Office of Financial Management (OFM) estimated that we'd require 85 million grams per year to start our legal cannabis industry. That number is based on 360,000 adults imbibing 117 times per year at two grams a toke—extrapolations based on national survey data and a UN report. That's more than half an ounce for every adult Washingtonian.

The state needs a reliable figure so it can issue enough licenses to growers. If it gets this wrong, legal pot stores could run dry.

Dr. Dominic Corva, politics faculty at Sarah Lawrence College, said the OFM's methodology is imperfect, but "there is no other credible way to do this." The task distills to correctly estimating users, frequency, and grams.

"To suggest that two grams is an average use seems laughable," remarks cannabis researcher Dr. Michelle Sexton. Her patients reported a typical use as one hit, around one-tenth of a gram.

Pot surveys also have inherent flaws, said cannabis expert Dr. Sunil Aggarwal, because some people lie about illegal drug use. He advised, "The best way to estimate population use is to sample sewers for metabolites and back-calculate how much must have been collectively consumed." Shitty methodology—but it could work.

Whatever numbers our cannabis consultant plugs into the pot equation, he or she must address two things omitted by OFM: consumption of pot food and the oncoming wave of cannabis tourists. With more annual visitors than citizens, Washington State can expect half a million out-of-towners chillin' on our grass.