Estimating the dollar value of the illicit market for cannabis in New Zealand

New data collected on the procurement and purchase of cannabis in the 2001 New Zealand National Drug Survey are used to estimate the dollar value of the illicit market for cannabis as well conduct other economic analyses of the illicit purchase of cannabis in New Zealand. Eighty-four per cent of last-year cannabis users received at least some of their cannabis 'free', 38% 'bought' at least some of their cannabis, while only 8% grew any of their supply. By proportion of the total dollar value of the cannabis market, sales of 'tinnies' (1.5 g) had the biggest share of the market (30%), followed closely by 50 NZ dollars bags (4 g) (29%) and ounces (28 g) (26%). The average price paid per gram of cannabis fell steadily from 20.50 NZ dollars per gram for a joint to 5.63 per gram for a pound (NZ dollars). The distribution of spending on cannabis was positively skewed (average 1313 NZ dollars, median 400 NZ dollars, mode 100, range 5 - 55,200, interquartile range 100 - 1200) (NZ dollars). The bottom 50% of cannabis buyers spent a median amount on cannabis of 100 NZ dollars a year while the top 5% spent a median amount of 7425 a year (NZ dollars). The dollar value of the illicit cannabis market was estimated to be 190 million (131 - 249 million) (NZ dollars). Three limitations are acknowledged with the market estimate calculated: (i) the truncated age range of the survey data (13 - 45 years); (ii) the likely underestimation of heavy cannabis use in household drug surveys; (iii) a degree of 'double-counting' when the same cannabis is bought and sold a number of times.