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Kerrand Ye Journal of Cannabis Research (2022) 4:35
https://doi.org/10.1186/s42238-022-00147-8
ORIGINAL RESEARCH
Characteristics oftheWashington cannabis
market from2014 to2016
William C. Kerr* and Yu Ye
Abstract
Background: The state of Washington legalized cannabis for adult use in 2012 and retail stores began to open in
2014. While details of the legal market have been tracked by the state, the total market for cannabis and characteris-
tics of purchasers can only be identified through surveys.
Methods: Six cross-sectional samples of the Privatization of Spirits in Washington (PSW) surveys were collected
between January 2014 and October 2016 with two in each year. Random digit dial procedures were used to recruit a
sample aged 18 and older, with 40% of cases from mobile phones. A total of 5492 respondents participated. Analyses
of the population-weighted sample utilized purchasing amounts and frequencies, use frequency and related meas-
ures to estimate total and mean amounts and expenditures. Sensitivity analyses were conducted for key assumptions.
Results: The market for cannabis flower is estimated to have increased from 158 metric tons and $1.23 billion in 2014
to 222 metric tons and $1.7 billion in 2016, with little change from 2014 to 2015. Purchases from legal sources, retail
and dispensaries, were estimated at 69% of the total market. Daily or near daily (DND) users accounted for about 83%
of sales in 2014, rising to 91% in 2016. The prevalence of past year use rose substantially from 25% in 2014 to 32% in
2016, with DND use rising from 10.2 to 11.3%. Average purchase amounts for DND users rose from 291 g in 2014 to
374 g in 2016, while mean amounts among non-DND users declined from 78 to 28.6 g.
Conclusions: The expansion of retail cannabis stores in Washington appears to have led to increased market size
in 2016 with all of the increase attributed to DND users. Frequent users may be important to consider in legalization
evaluations.
Keywords: Cannabis, Marijuana, Market share, Legal, Illegal, Washington State, Marijuana products
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Background
With cannabis for adult use becoming legal in an increas-
ing number of states, issues related to the transition from
illicit to legal cannabis markets are a significant research
priority. Key questions regarding the impacts of cannabis
legalization include the degree to which purchasing will
shift from the illicit market and the how the market will
grow and change. Estimating the size of illicit markets
is difficult, but general population surveys offer what is
possibly the best opportunity for this in states where can-
nabis use is legal and where cannabis can be purchased in
retail stores. Prior studies have utilized frequency of use
data from the National Surveys on Drug Use and Health
(NSDUH) series along with data from other sources to
estimate use amounts and expenditures (Caulkins etal.
2019) and data on purchasing in the NSDUH to estimate
sales and other aspects of how marijuana is obtained in
the USA (Davenport and Caulkins 2016).
National trends in cannabis use show a steady increase
in past year use prevalence among those 12 and older
from 10.1% in 2007 to 15.9% in 2018, with a similar
increase in past month use (Substance Abuse and Mental
Health Services Administration2018). In a national study
Open Access
Journal of Cannabis
Research
*Correspondence: wkerr@arg.org
Alcohol Research Group, Public Health Institute, 6001 Shellmound Ave, Suite
450, Emeryville, CA 94608, USA
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Kerrand Ye Journal of Cannabis Research (2022) 4:35
of marijuana trends utilizing age-period-cohort decom-
position in models with sociodemographic and canna-
bis policy measures to identify sources of marijuana use
prevalence variation over the 1984–2015 period, it was
found that the increased use rates through 2015 could
be attributed to general period effects rather than spe-
cific state policy changes (Kerr etal. 2018). However, few
states had adopted legalization in that period and the
varying details of medical use laws make those difficult
to evaluate. Nonetheless, it appears that more general
changes in attitudes regarding marijuana was an impor-
tant factor (Stringer and Maggard 2016).
Legalization in the state of Washington was passed in
2012 but retail stores did not open until July of 2014, with
31 stores open by the end of August, then rising to 311
stores open as of September 2016. Washington already
allowed medical use for a wide range of conditions with
dispensary sales and had an established illicit market
with high prevalence of use (Kerr et al. 2018). Wash-
ington adult use cannabis market regulations included
restrictions on store numbers, seed to sale tracing, bans
on home growing and delivery, and relatively high tax
rates, although taxes were simplified and reduced in 2015
(Cambron et al. 2017). Further restrictions including
temporary and permanent bans on stores and location
restrictions were also in place at local levels (Dilley etal.
2017).
Prior analyses from the same Washington survey series
utilized here have provided insights into changes in can-
nabis use and related attitudes during the early years of
the legal retail market. Use prevalence did not substan-
tially increase with adult use legalization from 2012 to
2014 and 2015 (Kerr etal. 2018), but, in 2016 use preva-
lence did increase significantly (Subbaraman and Kerr
2020). Other results from the same survey series found
that prevalence rates of marijuana harms from others’
use were flat from 2014 to 2016 (Kerr etal. 2021) and that
variation in individual’s alcohol and cannabis use in the
linked longitudinal sample indicated that more frequent
cannabis use was tied to risky drinking (Kerr etal. 2019).
Furthermore, voters support for legalization was shown
to increase after implementation among those who voted
both for and against I502, the initiative establishing legal
adult use (Subbaraman and Kerr 2016), and population
support for cannabis legalization in Washington contin-
ued to increase to 78% in 2016 (Subbaraman and Kerr
2017).
Studies of the Washington market have found
increased use over time after adult use legalization. A
study utilizing analyses of raw wastewater sample from
2014 to 2016 found evidence of increasing use in 2016,
consistent with survey results (Burgard etal. 2019). A
study utilizing the Behavioral Risk Factor Surveillance
System survey for Washington found increased use and
frequent use after legalization to be associated with
access to retail stores, rather than legalization or store
opening generally (Everson etal. 2019). e details of
cannabis purchases in the legal market from 2014 to
2016 have also been evaluated finding that the pur-
chases mostly involved high-THC cannabis flower with
a growing share of cannabis extracts and a declining
price per gram, particularly from 2014 to 2015 (Smart
etal. 2017).
e current study presents estimates of cannabis mar-
ket trends in purchasing, purchase frequency, amounts,
and types and total market size for Washington from
2014 to 2016 as retail stores opened. ese estimates are
relevant to understanding the early development of can-
nabis markets after legalization and store openings and
for considering the implications of legalization on illicit
markets and population use patterns. Highlighting user
and purchaser characteristics related to more frequent
use, large purchase amounts, and providing cannabis to
others are also needed for developing and targeting pre-
vention and harm reduction efforts.
Methods
Sample
e series of Privatization of Spirits in Washington
(PSW) Surveys, conducted between January 2014 and
December 2016 by ICF International, was designed to
evaluate impacts over time of the privatization of spirits
sales and the legalization of marijuana in Washington
state. e data analyzed consist of six cross-sectional
representative surveys of adults (aged 18 and over), with
sample recruitment taking place separately in Janu-
ary–April 2014 (Wave 1, N = 1202), Septemb er–Octo-
ber 2014 (Wave 2, N = 804), March–May 2015 (Wave
3, N = 823), August–October 2015 (Wave 4, N = 662),
March–April 2016 (Wave 5, N = 610), and Septem-
ber–December 2016 (Wave 6, N = 1391). At each wave,
respondents were selected using a state random prob-
ability sample obtained via random digit dial (RDD) of
both landline and cell phone samples with about 40% cell
phones. Respondent self-identified as adult Washington
residents. e AAPOR2 cooperation rates (e Ameri-
can Association for Public OpinionResearch2011) (com-
plete and partial interviews as a percentage of identified
eligible respondents) were (landline, cell): Wave 1 (50.8%,
59.5%), Wave 2 (45.8%, 62.4%), Wave 3 (43.7%, 61.5%),
Wave 4 (41.7%, 59.6%), Wave 5 (49.4%, 60.9%), and Wave
6 (45.3%, 63.0%). Surveys lasted about half an hour on
average and respondents received $10 gift cards. Proto-
cols were approved by the Public Health Institute Institu-
tional Review Board (#I13-010).
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Kerrand Ye Journal of Cannabis Research (2022) 4:35
Measures
Past‑year (PY) marijuana user
Past-year (PY) marijuana user was determined using the
question: “How often have you used marijuana, hash or
pot during the last twelve months,” with selection options
including “Every day or nearly every day,” “About once
a week,” “Once every 2 or 3weeks,” “Once every month
or two,” “less often than that,” and “Never last year.”
Respondents were coded as dichotomous PY marijuana
users or not. PY use was further classified into Daily or
Nearly Daily (DND) users (those who answered “every
day or nearly every day”) and non-DND users. Mode of
marijuana use was elicited by the question “how do you
most commonly consume marijuana” and categorized
as smoke, inhalable (vaporize marijuana, hashish, resin,
oil, wax, or dabs), edible (food product or beverage),
and other product (tincture, lotion, salve, balm, spray, or
other).
PY ower (raw marijuana) purchasing quantity
andexpenditure
All PY marijuana users were asked “how often do you
usually purchase marijuana” with categorical responses
recoded as the number of days purchased PY. Marijuana
flower amount (in grams) usually purchased was based
on the question: “what amount of raw Marijuana do you
usually buy”, with selection options ranging from “0.5 g
(Nickel Bag)” to “an ounce (28g),” and including “Other:
Specify” where respondents provide the specific amount.
To elicit expenditure, purchasers were then asked “about
how much this amount cost,” and provided the dollar
amount for the usual marijuana flower purchase. Aver-
age $ per gram of marijuana flower was derived divid-
ing usual expenditure on usual flower purchase quantity.
Cleaning of expenditure data involved editing noticeable
typos and adjusting for potential outliers by truncat-
ing average $ per gram at the 5th and 95th percentiles.
Across six waves there were 1177 PY marijuana users,
and 769 reported purchasing at least once PY. Among
them, 59 reported “Never” for usual purchase quantity
without valid usual expenditure. ey were excluded
from the final definition of flower purchaser (n = 710).
Total quantity (in grams) of marijuana flower purchased
PY was derived multiplying the usual grams of marijuana
flower purchased by the number of days marijuana was
purchased, assuming each trip involved a marijuana
flower purchase. In a sensitivity analysis, we adjusted
for potential overestimation by accounting for trips pur-
chasing other marijuana products (described below).
Fifty-two respondents reported valid usual expenditure
but were missing usual purchase quantity. eir usual
quantity was imputed by dividing usual expenditure by
the sample median $ per gram. For those who reported
usual quantity but were missing on expenditure (n = 45
across six waves), their usual expenditure was imputed by
multiplying usual quantity by sample median $ per gram
as well. Finally, 16 flower purchasers missing both pur-
chase usual quantity and expenditure were assigned the
sample median on both measures. Total $ expenditure on
marijuana flower PY was then calculated multiplying the
usual expenditure on flower by the number of days mari-
juana was purchased.
Other marijuana product purchases
All PY marijuana users were asked “how often do you
usually purchase marijuana-related products such as
hash, oil, edibles, teas or lotions” and coded as PY pur-
chaser of other marijuana products or not and number
of days other marijuana products were purchased. Each
purchaser was then asked to provide the amount usually
bought and how much that amount costs for up to three
products. Across six waves there were 391 PY other mar-
ijuana product purchasers of whom 240 reported usual
expenditure for one product, 64 for two products, and 38
for three products. For those purchasing more than one
product, we estimated the usual expenditure assuming
that half of the time the products were purchased sepa-
rately and the other half of the time the products were
purchased together. 49 respondents who were other
marijuana product purchasers but were missing on usual
expenditure were assigned the sample median. Sensitiv-
ity analyses also considered the average (assuming all
products purchased separately with equal probability)
and the summation (assuming all products purchased
together) of costs across products. PY total expenditure
on other marijuana products was calculated from the
usual expenditure and number of purchase days.
Purchase atalegal retail store (Wave 2–6)
From Wave 2 (no stores had opened at Wave 1), each
marijuana user was asked “Since July 2014, have you pur-
chased marijuana, or other marijuana products from a
legal retail store in Washington.” For the Wave 5 and 6
surveys in 2016, three items were added for marijuana
users: “Within last 12months, what proportion of your
marijuana purchases were from…”: “a legal store in Wash-
ington,” “a medical dispensary in Washington,” and “other
sources” with options of “none,” “less than half,” “about
half,” “most,” or “all.” ese responses were converted to
proportions (i.e., 0%, 25%, 50%, 75%, and 100%, respec-
tively), multiplied by self-reported purchasing quantity
and expenditure on marijuana flower to estimate the
flower market size from store sales (i.e., sales from both
legal retail stores and medical dispensaries) and from the
illegal market (i.e. sales from “other sources”) in 2016.
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Kerrand Ye Journal of Cannabis Research (2022) 4:35
Statistical analyses
e two cross-sectional waves in each year were com-
bined to generate data for years 2014, 2015, and 2016
separately. Merging each two waves adjusts for poten-
tial seasonal fluctuations in marijuana use and purchase
behavior, and enhances stability with larger sample size.
Sample proportions and means for population preva-
lence and average estimates are presented. To test trend
effects, regressions with survey year as a continuous pre-
dictor were estimated. Marijuana market size estimates
aggregated individual quantities applying the population
weights. All analyses were performed with STATA ver-
sion 15 survey commands (StataCorp. 2017).
e data were weighted to adjust for probability of
selection introduced during the sampling design and also
to post-stratify and adjust the sample to match the tar-
get population. First, base weights were constructed for
landline and cell phone samples separately to reflect the
number of phones and number of adults for each house-
hold (landline sample) or individual number of phones
(cell sample) Second, the landline and cell sample were
combined to reflect the population coverage of landline
and cell sample frames. e respondents were weighted
to National Health Interview Survey state benchmarks
based on their landline/cell usage status. Last, the
weighted data were calibrated to reflect population dis-
tributions from the American Community Survey, using
a raking adjustment for the following dimensions: sex by
age, age by race/ethnicity, and education levels. For the
combined cross-section data for 2014, 2015, and 2016
separately, the final weighted sample represents all adults
(18 and older) residing in the State of Washington in the
given year.
Several sensitivity analyses were performed. First, to
adjust for potential overestimation of the marijuana
flower market size, since purchasing frequency of mari-
juana flower was not specifically asked, the number of
days marijuana flower was purchased was re-derived for
PY marijuana users whose most commonly used product
was not a smoked product (i.e., inhalable, edible, or oth-
ers). eir flower purchasing frequency was re-estimated
by taking the larger value of (1) the difference between
the number of days marijuana was purchased and the
number of days other marijuana products were pur-
chased or (2) half of the days marijuana was purchased.
Furthermore, we re-estimated the market size for other
marijuana products, re-calculating the usual expenditure
as the average and summation when the respondents
reported more than one product was usually purchased.
Results
Table 1 shows the prevalence of PY marijuana use and
purchases of flower and other marijuana products by
Washington residents for 2014–2016. Prevalence of PY
Table 1 Trends in marijuana use and purchasing for Washington state from 2014 to 2016
a Trend test is performed tting logistic regressions predicting each dichotomous outcome using year as a continuous predicting variable
b Among PY users only
c Marijuana purchase questions were only asked if the respondent was a PY user
d Including marijuana ower or marijuana products, and only asked if the respondent was a PY user. Only wave 2 data were used for 2014, excluding wave 1 data as
the survey was conducted before any store was opened
2014 2015 2016 Trend test a
Past year (PY) users—any marijuana use 24.9% 26.2% 31.7% P = 0.002
Daily/nearly daily (DND) marijuana user 10.2% 10.2% 11.3% P = 0.514
DND user among PY users 41.1% 38.9% 35.7% P = 0.252
Most common product type usedb
Smoked 80.9% 70.7% 72.9% P = 0.049
Inhalable 9.5% 14.4% 12.3% P = 0.387
Edible 8.2% 13.2% 11.9% P = 0.159
Others 1.4% 1.8% 2.9% P = 0.192
Any marijuana flower purchase PY 14.9% 16.7% 21.8% P < 0.001
Any flower purchase among PY usersc60.3% 64.0% 68.8% P = 0.052
Any flower purchase among DND users 82.7% 89.6% 87.3% P = 0.465
Any other marijuana product purchase PY 8.0% 8.9% 13.0% P = 0.003
Any other product purchase among PY users 32.7% 34.2% 41.0% P = 0.075
Any other product purchase among DND users 50.4% 54.9% 54.1% P = 0.672
Ever purchased at retail store among PY usersd23.4% 41.4% 65.1% P < 0.001
Ever purchased at retail store among DND users 34.7% 54.7% 85.4% P < 0.001
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Kerrand Ye Journal of Cannabis Research (2022) 4:35
marijuana use increased from 24.9% in 2014 to 31.7% in
2016 among those aged 18 + . No significant trend was
observed for DND use, however, increasing slightly from
10.2 to 11.3%. Among PY marijuana users the most com-
monly used product type was smoked, which significantly
decreased over time (80.1% in 2014 to 72.9% in 2016). For
the three years combined, DND users were more likely
to report smoked (79.8% vs 71.2% among non-DND
users) and inhalable (15.9% vs 9.7%) as their most com-
monly used product, and less likely to use edibles (3.4%
vs 16.2%) (data not shown). A significant increase in
prevalence of PY marijuana flower purchases was also
observed (14.9% to 21.8% 2014–2016). Similarly, PY pur-
chases of other marijuana products increased from 8.0%
in 2014 to 13.0% in 2016. In 2014 at Wave 2, only 23.4% of
PY users had purchased at a legal retail store, increasing
substantially to 65.1% in 2016.
Table2 presents the sample means and standard errors
for the marijuana flower and other marijuana product
purchase measures across 2014–2016, and also separately
by DND and non-DND users. Across years, there were
only a few significant trends observed, all among non-
DND users including a decrease in the number of days
flower was purchased and lower total grams of flower
purchased. ere were clear differences between DND
and non-DND users in purchasing behaviors. Compared
to non-DND users, the flower purchasing days of DND
users were about 2–4 times greater and the usual grams
of marijuana flower purchased was about double. e
mean price of marijuana flower paid by DND users was
$5.2 per gram less than for non-DND users in 2014 with
this gap shrinking to about $2.6 in 2016. DND users also
purchased other marijuana products more frequently
and spent more on each purchase, with the exception of
2016 where the mean usual expenditure spent on other
marijuana products was similar to non-DND users ($36.3
vs $38.7).
Table 3 shows the total market size for marijuana
flower and other marijuana products in Washington
across 2014–2016 and by user frequency groups. We
estimate that the marijuana flower market size in Wash-
ington was 158 metric tons (MT) in 2014 and increased
to 222 MT in 2016. All DND users purchased 130 MT
in 2014, increasing to 203 MT in 2016, representing
82–91% of total flower sales in quantity across the 3years
(88% for the three years combined). Total expenditure
on marijuana flower was about $1.23 billion ($0.97 bil-
lion by DND users) in 2014 and increased to $1.70 billion
Table 2 Means (SE) for marijuana flower and other marijuana products purchase quantity, frequency, and expenditure for Washington
state 2014–2016
a For PY marijuana ower purchasers (n = 710)
b For PY marijuana ower purchasers excluding 16 respondents reporting neither valid usual quantity nor valid expenditure (n = 694)
c For PY marijuana ower purchasers who reported both valid usual quantity and expenditure (n = 597)
d For PY purchasers of other marijuana product (n = 391)
e For PY purchasers of other marijuana product excluding 49 respondents who did not report valid expenditure on other marijuana products (n = 342)
2014 2015 2016 Trend test
# days marijuana flower purchased PYa25.8 (2.3) 20.8 (2.5) 20.2 (2.2) P = 0.098
- For daily/nearly daily (DND) users 33.7 (3.2) 31.5 (4.0) 34.6 (3.8) P = 0.838
- For non-DND users 15.4 (3.0) 8.0 (1.0) 8.3 (1.0) P = 0.029
Grams of marijuana flower usually purchasedb13.7 (4.7) 9.8 (1.6) 7.3 (1.0) P = 0.158
- For DND users 17.7 (7.7) 13.1 (2.6) 10.1 (1.9) P = 0.327
- For non-DND users 8.3 (3.6) 5.7 (1.3) 4.9 (0.9) P = 0.340
Total grams marijuana flower purchased PYb202 (27) 165 (27) 186 (68) P = 0.882
- For DND users 294 (41) 270 (44) 374 (142) P = 0.581
- For non-DND users 78.0 (24.1) 36.8 (8.2) 29.6 (4.6) P = 0.044
$ per gram for usual marijuana flower purchasec11.5 (0.8) 13.6 (0.9) 11.5 (0.5) P = 0.786
- For DND users 9.3 (1.0) 11.7 (1.2) 10.1 (0.5) P = 0.543
- For non-DND users 14.5 (1.2) 16.0 (1.3) 12.7 (0.8) P = 0.120
# days other marijuana product purchased PYd17.0 (3.4) 15.2 (2.7) 11.2 (1.7) P = 0.098
- For DND users 22.5 (5.2) 21.4 (4.0) 15.3 (3.2) P = 0.225
- For non-DND users 7.9 (1.5) 5.0 (0.9) 7.6 (1.3) P = 0.877
$ usually spent purchasing other marijuana productse33.2 (5.6) 41.3 (7.8) 37.5 (4.9) P = 0.668
- For DND users 38.4 (8.1) 48.8 (11.6) 36.3 (4.7) P = 0.730
- For non-DND users 22.7 (3.7) 27.5 (3.7) 38.7 (8.5) P = 0.100
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Kerrand Ye Journal of Cannabis Research (2022) 4:35
($1.52 billion by DND users) in 2016. e proportion
of total expenditure on flower purchased by DND users
ranged from 79 to 89% (86% for three years combined).
e mean market price of marijuana flower was $7.81 per
gram in 2014, increased to $8.68 in 2015, and dropped
back to $7.65 per gram in 2016. Note that the market
price reported in Table3, derived by dividing the total
market dollar expenditures by total market quantity, was
lower than the average price among purchasers reported
in Table2, which was the sample mean. e total expend-
iture on other marijuana products in Washington was
estimated at $0.44 billion ($0.41 billion by DND users,
93%) in 2014, declining to $0.33 billion ($0.22 billion by
DND users, 67%) in 2016, with purchases by DND users
representing 84% of total expenditure for three years
combined. Taken together, the results show that the
marijuana market in Washington has grown substan-
tially since retail stores began to open in 2014, by 40.5%
for marijuana flower quantity (158 to 222 MT) and 21.5%
for total expenditures, including both flower and other
marijuana products ($1.67 to $2.03 billion). Several sen-
sitivity analyses were performed for market size estima-
tion. First, when accounting for potential overestimation
of flower purchasing frequency, the re-estimated flower
purchasing quantity was 145, 135, and 218 MT across
2014–2016, while the re-estimated flower expenditure
was 1.15, 1.17, and 1.67 billion dollars across the three
years. For the market size of other marijuana products,
when usual expenditure was estimated by taking the aver-
age for multiple products, the re-estimated total expendi-
ture was 0.38, 0.30, and 0.24 billion dollars for years
2014–2016; when taking the summation across multiple
products, the re-estimated total expenditure was 0.50,
0.48, and 0.41 billion dollars across the years (not shown).
Finally, using the 2016 data only, PY total expenditure
on marijuana flower based on store sales (including sales
from both legal retail stores and medical dispensaries)
was estimated at $1.24 billion, representing 73% of the
$1.70 billion total expenditure from the 2016 PSW sur-
veys ($1.14 billion by DND users and $0.11 billion by
non-DND users). Likewise, the total market size for mar-
ijuana flower quantity from store sales was estimated at
153 MT, 69% of the 222 MT total quantity based on the
2016 survey (143 and 10.3 MT by DND and non-DND
users, respectively). e remaining 27% of expenditures
and 31% of quantity purchased from “other sources” was
the estimated market share of the illegal market.
Discussion
ese 2014–2016 market size estimates and analyses of
purchasing behaviors for the state of Washington (age
18 +) build on the small number of population stud-
ies addressing marijuana buying and use in a legal-
ized market. is study is the first to provide estimates
directly from a representative sample of a state during
the early years of retail store openings. Surveys are an
important tool for estimating and tracking legal and ille-
gal marijuana use and appear to be more accurate after
legalization (Kerr et al. 2018). Furthermore, marijuana
purchasing and use appear to be very concentrated
among the heaviest users, like alcohol and many other
products.
Our results are reasonably similar to prior stud-
ies utilizing different data. An analysis by Caulkins and
Table 3 Total market size estimates (95% CIs) for marijuana flower quantity and expenditure and for other marijuana product
expenditure for Washington state from 2014 to 2016
a For PY marijuana ower purchasers (n = 710). Among them, 16 respondents reported neither valid usual quantity nor valid expenditure and the measures were
imputed using sample median
b For PY purchasers of other marijuana product (n = 391). Among them, 49 respondents whose expenditure on other marijuana products were missing and the
measure was imputed using sample median
2014 2015 2016
Total marijuana flower purchased (metric tons)a158 (106, 209) 148 (93, 204) 222 (58, 387)
- For daily/nearly daily (DND) users 130 (82, 179) 133 (79, 187) 203 (39, 367)
- Dor non-DND users 27.0 (10.3, 43.7) 15.1 (7.9, 22.2) 19.3 (12.1, 26.5)
Total expenditure on marijuana flower (billion $)a1.23 (0.87, 1.59) 1.29 (0.83, 1.75) 1.70 (0.47, 2.93)
- For DND users 0.97 (0.65, 1.28) 1.15 (0.70, 1.60) 1.52 (0.29, 2.74)
- For non-DND users 0.26 (0.10, 0.43) 0.14 (0.08, 0.20) 0.18 (0.12, 0.25)
$ per gram of usual marijuana flower a$7.81 $8.68 $7.65
- For DND users $7.41 $8.61 $7.48
- For non-DND users $9.77 $9.35 $9.53
Total expenditure other marijuana products (billion $)b0.44 (0.09, 0.80) 0.39 (0.17, 0.60) 0.33 (0.17, 0.49)
- For DND users 0.41 (0.05, 0.76) 0.35 (0.14, 0.57) 0.22 (0.07, 0.38)
- For non-DND users 0.04 (0.02, 0.05) 0.03 (0.01, 0.06) 0.10 (0.06, 0.15)
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Kerrand Ye Journal of Cannabis Research (2022) 4:35
colleagues of the Washington market used the 2015–
2016 NSDUH surveys and RAND’s 2013 survey of Wash-
ington cannabis users to estimate market size and found
a total market size of 208 MT for Washington in 2016,
worth $1.66 billion (Caulkins etal. 2019). ese amounts
are comparable to, but lower than, our estimates of $2.0
billion on all products and 222 metric tons of marijuana
flower. RAND estimates for 2016–2017 were higher at
252 MT for total market size reflecting the increased use
seen for 2016 in the PSW survey and for 2016–2017 in
the NSDUH survey (Kilmer etal. 2019). It is notable that
population estimates of total alcohol consumption from
survey use measures are typically 40–60% of sales figures
(Nelson etal. 2010; Kerr, etal. 2010), suggesting that can-
nabis market estimates based on surveys are also likely
to be conservative. Our estimates for 2016 also indicate
that about 31% of the marijuana sold in Washington
came from outside the legal retail system, indicating that
the legal system provided the most, but still far from all,
of the total market. Comparison of the prices paid for
flower in the surveys with those in the Washington track-
and-trace system show that they became more similar
over time. e system prices were $4.79 higher per gram
in 2014, but declined over time and were slightly lower
in 2016 at $7.20 per gram compared to $7.65 in the PSW
surveys (Davenport 2021). e declining system prices
were due to both increased supply of cannabis and the
2015 tax reduction. Total expenditure in 2016 in the sys-
tem was $969 million compared to $2.03 billion in the
surveys, suggesting that about $411 million was spent in
dispensaries, which remained open until June of 2016,
and $620 million was spent in the illicit market.
A key finding was that daily and near daily (DND) users
bought 91% of the marijuana flower in 2016 and spent
89% of the dollars spent on other marijuana products.
e high proportion of cannabis sold to DND users also
suggests that they are the main providers of cannabis to
the 25% of users who did not purchase in the past year.
Prior studies have also highlighted the importance of
DND users: A US study (Davenport and Caulkins 2016)
found that they used 77% of the cannabis in 2012–2013.
An Australian study also found daily users accounted
for 85% of the cannabis in 2016 (Chan and Hall 2020).
ese findings indicate that the cannabis market is
largely driven by DND users and that the concentration
of purchasing in this group does not decline, and per-
haps increases, after legalization. In our results there was
a reduction in the proportion of past year users who are
DND from about 41% to 36% in 2016 as the prevalence of
past year use increased, indicating that most new users
had lower frequencies.
ere are a number of limitations to this study includ-
ing the use of self-reported purchasing behavior, which
may be mis-remembered or under-reported due to social
desirability bias and concerns about reporting illegal
activities for illicit market purchases (Kerr et al. 2018).
ere may also be under-reporting due to non-response
if heavier cannabis users/purchasers were less likely to
participate in the surveys as is the case for alcohol (Tolo-
nen et al. 2019). While this is likely also the case for
stronger drugs such as heroin it is not clear whether this
would apply to cannabis users. Our analyses also required
some strong assumptions regarding the interpretation of
reported frequency of purchases and the relationships
between the most recent purchase and other purchases.
e use of recent purchase questions is supported by a
study that included multiple purchases and found that
the most recent was representative of other purchases
(Bond etal. 2014).
Surveys of purchasing behaviors offer a unique and
important perspective on marijuana markets in states
with legal use enabling tracking of the shift from illicit
to legal markets and the expansion of purchasing among
users. Surveys are also needed to understand purchaser
characteristics and the concentration of activities among
certain types of users/purchasers. ere is a need for
more detailed monitoring surveys such as ours to track
behaviors in states adopting retail marijuana markets.
ese should include more details on products and pur-
chasing patterns than was possible in our PSW surveys,
which were designed primarily to capture alcohol use
and purchasing. Other marijuana products, particu-
larly concentrates, vape pens, and edibles, have become
more popular in recent years increasing the importance
of more detailed assessment and tracking (Schauer etal.
2016; Carlini etal. 2020).
Conclusions
is study utilized the 2014–2016 PSW surveys to esti-
mate the total market size for cannabis flower and
other cannabis products in each year with individually-
reported data from within the surveys only, with results
similar to those from prior estimates that used multiple
sources. e cannabis market was shown to increase
over time, particularly in 2016 when the full complement
of retail stores were open with an estimated 70% of can-
nabis purchased legally in that year. Detailed analyses of
cannabis purchasing behaviors highlight the importance
of DND users who accounted for most of the purchases
in each year. ese results emphasize the importance of
focusing prevention and intervention efforts on 10–11%
of the population who are DND users who not only
account for the majority of cannabis use but also likely
provide most of the cannabis to the 25% of past-year
users who did not purchase any themselves.
Page 8 of 8
Kerrand Ye Journal of Cannabis Research (2022) 4:35
Abbreviations
NSDUH: National Survey on Drug Use and Health; DND: Daily or nearly daily;
MT: Metric tons; PY: Past year; RDD: Random digit dialed.
Acknowledgements
Not applicable.
Authors’ contributions
Both authors contributed significantly to study design, analyses, interpretation,
and manuscript writing. The author(s) read and approved the final manuscript.
Funding
This work was supported by the US National Institute on Drug Abuse (NIDA)
(R01 DA048526) and the US National Institute on Alcohol Abuse and Alcohol-
ism (NIAAA) (R01 AA021742) at the National Institutes of Health (NIH). Content
and opinions are those of authors and do not reflect official positions of NIDA,
NIAAA, or the National Institutes of Health.
Availability of data and materials
Data are not currently publicly available as the study is ongoing.
Declarations
Ethics approval and consent to participate
This study received ethical approval from the Public Health Institute’s Institu-
tional Review Board. All participants provided verbal consent.
Consent for publication
Not applicable.
Competing interests
The authors have no conflicts of interest, financial or otherwise, to declare.
Received: 29 September 2021 Accepted: 24 June 2022
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