Estimating cannabinoids sold from marijuana sales data in Washington state Watch me pull a number out of my hat Jason Williams 1 with assistance from Caleb Banta-Green 1 & Dan Burgard 2 1 Alcohol & Drug Abuse Institute University of Washington 2 Chemistry Department University of Puget Sound 20 March 2018 / ADAI Brown Bag Jason Williams (ADAI) Measuring THC 1 / 42
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Estimating cannabinoids sold from marijuana sales data in ...adai.uw.edu/pubs/pdf/2018THCdifficultiesandinitialsimpleestimate.pdfConcentrates GramsSold TotalTHC THC CBD THCA RetailProductName
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Estimating cannabinoids sold from marijuana sales data inWashington state
Watch me pull a number out of my hat
Jason Williams1
with assistance from Caleb Banta-Green1 & Dan Burgard2
1Alcohol & Drug Abuse InstituteUniversity of Washington2Chemistry Department
University of Puget Sound
20 March 2018 / ADAI Brown Bag
Jason Williams (ADAI) Measuring THC 1 / 42
Acknowledgments
Thanks to:The Washington State Dedicated Marijuana Fund for research at the University ofWashington for funding supportLooking Glass Analytics for flattening the database
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Today’s outline
1 ProblemsWhy would we want to know how much THC or other cannabinoids are being sold?How it should workSo what’s the problem?
2 SolutionsWhat do we need?Our approach
3 Results!King County, June 2016Pierce County, June 2016
Jason Williams (ADAI) Measuring THC 3 / 42
Outline
1 ProblemsWhy would we want to know how much THC or other cannabinoids are being sold?How it should workSo what’s the problem?
2 SolutionsWhat do we need?Our approach
3 Results!King County, June 2016Pierce County, June 2016
Jason Williams (ADAI) Measuring THC 4 / 42
Why measure cannabinoids?Important questions
Policy analysis To what extent does the THC sold via licensed stores account for the THCmetabolite found in wastewater, implying displacement of the illegal market?
Marketing studies To what extent is the market in Washington moving to higher potencyproducts?
Microeconomics What is the price elasticity of THC potency?Public health How much THC is out there, and where?
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This should be easyWe have the data...
Washington state Liquor and Cannabis Board (LCB) mandates use of a seed-to-saledatabase to
Track every plantFollow each plant as it is refined and turned into productsTrack testing results for every productAll to demonstrate products are not being diverted.Also, to facilitate excise tax collection, etc.
Jason Williams (ADAI) Measuring THC 6 / 42
This should be easyWe have the data...
Washington state Liquor and Cannabis Board (LCB) mandates use of a seed-to-saledatabase to
Track every plantFollow each plant as it is refined and turned into productsTrack testing results for every productAll to demonstrate products are not being diverted.Also, to facilitate excise tax collection, etc.
Jason Williams (ADAI) Measuring THC 6 / 42
Outline
1 ProblemsWhy would we want to know how much THC or other cannabinoids are being sold?How it should workSo what’s the problem?
2 SolutionsWhat do we need?Our approach
3 Results!King County, June 2016Pierce County, June 2016
Jason Williams (ADAI) Measuring THC 7 / 42
How it should workAlcohol example
Item Packages Sold Package Count ABV% Volume Per Count (L) Alcohol (L)
0.88203125 9.27 1.7 6.73 8.63 Third Kynde - CBD Preroll Third Kynde - CBD Preroll0.826498423 12.7 12.7 18.7 0 Third Kynde - CBD Preroll Third Kynde - CBD Preroll1 56.5 10.5 4.2 37.5 Golden Nuggets No. 5 Golden Nuggets No. 5
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So what’s the problem?In sum
1 No pack size.2 No unit of measurement for potencies required.3 Not clear whether potencies are per serving or per container.4 Inexplicable potencies.5 Idiosyncratic descriptors mean we can’t always pull useful information out of names.6 No instructions to labs for entering potencies.7 No data checking.
Jason Williams (ADAI) Measuring THC 25 / 42
So what’s the problem?In sum
1 No pack size.2 No unit of measurement for potencies required.3 Not clear whether potencies are per serving or per container.4 Inexplicable potencies.5 Idiosyncratic descriptors mean we can’t always pull useful information out of names.6 No instructions to labs for entering potencies.7 No data checking.
Jason Williams (ADAI) Measuring THC 25 / 42
So what’s the problem?In sum
1 No pack size.2 No unit of measurement for potencies required.3 Not clear whether potencies are per serving or per container.4 Inexplicable potencies.5 Idiosyncratic descriptors mean we can’t always pull useful information out of names.6 No instructions to labs for entering potencies.7 No data checking.
Jason Williams (ADAI) Measuring THC 25 / 42
So what’s the problem?In sum
1 No pack size.2 No unit of measurement for potencies required.3 Not clear whether potencies are per serving or per container.4 Inexplicable potencies.5 Idiosyncratic descriptors mean we can’t always pull useful information out of names.6 No instructions to labs for entering potencies.7 No data checking.
Jason Williams (ADAI) Measuring THC 25 / 42
So what’s the problem?In sum
1 No pack size.2 No unit of measurement for potencies required.3 Not clear whether potencies are per serving or per container.4 Inexplicable potencies.5 Idiosyncratic descriptors mean we can’t always pull useful information out of names.6 No instructions to labs for entering potencies.7 No data checking.
Jason Williams (ADAI) Measuring THC 25 / 42
Outline
1 ProblemsWhy would we want to know how much THC or other cannabinoids are being sold?How it should workSo what’s the problem?
2 SolutionsWhat do we need?Our approach
3 Results!King County, June 2016Pierce County, June 2016
Jason Williams (ADAI) Measuring THC 26 / 42
What do we need?Specifying required parameters
Total milligrams of THC sold =For each product i , amount of product× THC
unit of product =∑ni=1 Package Counti × Packages Soldi × Potency Per Counti ×
Scaling Factori
or∑ni=1 Grams Soldi × mg THC
g Product i
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What do we need?Specifying required parameters
Pull pack size from names?Get some idea of potency from names?How identify nonsensical potencies versus legitimately low or high values?Total THCi = THCi + .877× THCAi
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Outline
1 ProblemsWhy would we want to know how much THC or other cannabinoids are being sold?How it should workSo what’s the problem?
2 SolutionsWhat do we need?Our approach
3 Results!King County, June 2016Pierce County, June 2016
Jason Williams (ADAI) Measuring THC 29 / 42
Our approachSpecifying required parameters
1 Specify allowable high and low values (brackets) for pack size and potencyBy product typeTry to differentiate high CBD products?
2 Set everything outside those brackets to missing.3 Impute missing data from data we "trust".4 Vary assumptions to calculate a set of estimates.
Jason Williams (ADAI) Measuring THC 30 / 42
Our approachSpecifying required parameters
1 Specify allowable high and low values (brackets) for pack size and potencyBy product typeTry to differentiate high CBD products?
2 Set everything outside those brackets to missing.3 Impute missing data from data we "trust".4 Vary assumptions to calculate a set of estimates.
Jason Williams (ADAI) Measuring THC 30 / 42
Our approachSpecifying required parameters
1 Specify allowable high and low values (brackets) for pack size and potencyBy product typeTry to differentiate high CBD products?
2 Set everything outside those brackets to missing.3 Impute missing data from data we "trust".4 Vary assumptions to calculate a set of estimates.
Jason Williams (ADAI) Measuring THC 30 / 42
Our approachSimple version
Product type: pre-calculationsteps Pack size Packages sold THC potency
Solid edibles (22) Plug in median for missing PackagesSold Plug in median for missingHigh 20 12mgLow 1 1mg
Liquid edibles (23): Replace200mg (nominally 1:1) with100mg to represent THC
Assume all potencies arefor whole bottle, thereforepack size = 1
PackagesSoldUse marketing mg per bot-tle. Plug in median for miss-ing.
High 1 100mgLow 1 9mg
Concentrates (24) Sold by weight, thereforepack size = 1
GramsSold; ignorenominal weight innames
Plug in median for missing
High 1 98%bwLow 1 2%bw
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Our approachSimple version
Product type Pack size Packages sold THC potency
Topicals (25) IGNOR-ING
Assume all potencies are forwhole package, therefore packsize = 1
PackagesSold Single guess for all = 50mg?
Bud (28) Sold by weight, therefore packsize = 1 GramsSold Plug in median for missing
High 1 40%bwLow 1 0.6%bw
Mix package (31) Sold by weight, therefore packsize = 1 GramsSold Plug in median for missing
High 1 50%bwLow 1 0.6%bw
Mix infused (32) Sold by weight, therefore packsize = 1 GramsSold Plug in median for missing
High 1 70%bwLow 1 8%bw
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Our approachSimple version
For any sales entry missing one or more parameter, plug in:1 Lowest possible value2 Middle possible value (median of those values within brackets)3 Highest possible value
Calculate 3 values of mg THC for each sales entryFor complete and trusted sales, low = medium = highSum→ 3 estimated values of THC sold
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Our approachSimple version
For any sales entry missing one or more parameter, plug in:1 Lowest possible value2 Middle possible value (median of those values within brackets)3 Highest possible value
Calculate 3 values of mg THC for each sales entryFor complete and trusted sales, low = medium = highSum→ 3 estimated values of THC sold
Jason Williams (ADAI) Measuring THC 33 / 42
Our approachSimple version
For any sales entry missing one or more parameter, plug in:1 Lowest possible value2 Middle possible value (median of those values within brackets)3 Highest possible value
Calculate 3 values of mg THC for each sales entryFor complete and trusted sales, low = medium = highSum→ 3 estimated values of THC sold
Jason Williams (ADAI) Measuring THC 33 / 42
Outline
1 ProblemsWhy would we want to know how much THC or other cannabinoids are being sold?How it should workSo what’s the problem?
2 SolutionsWhat do we need?Our approach
3 Results!King County, June 2016Pierce County, June 2016
Total 152,304,999 153,164,908 155,336,671mg difference vs. middle -859,909 2,171,763% difference vs. middle -0.56% 1.42%
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Results!Comparing estimates accounting for population size
mg per capita
King
Pierce
176 178 180 182 184 186 188 190
182.1
181.4
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Summary
The sales data are problematicNo field for package sizeNo consistent indicator of high CBD productPotency problems
With certain assumptions, can still say something about salesBracket approach still puts trust in values within brackets
Possible improvementsFlag high CBD items based on some minimum CBD potency and/or "CBD"? Would missmany "medicinal" products.Confidence intervals via Monte Carlo simulation? High and low bounds < 3.5% wide, sovalue of "better" CIs unclear.
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Summary
Next step Comparing sales data to consumption estimates from wastewater testing forsame time periods and same place