Table 2

Methods used to estimate the ITTP in Canada

MethodStrengthsWeaknessesNo of studies*
Smoker surveys Buyers of smuggled tobacco have little or no legal incentive to conceal their behaviour (but analysis must still consider validity challenges listed under weaknesses); anonymity can be protected; direct method.Relies on self-reported data which may presents validity problems in that respondents may under-report a behaviour viewed as socially unacceptable, may not know if product is licit or illicit or may not remember; previous studies have found smokers under-report tobacco consumption; representative sampling requires specific expertise; expensive and time consuming.15
Residual methods Useful in countries with reliable and consistent estimates of tobacco consumption and sales over time; relies on well documented information; provable and reproducible; relatively inexpensive; useful in detecting deviations from the trend.Relies on assumptions about tax paid sales and consumption estimates; reliant on quality and availability of survey data; comparisons may not consider tourists or migrants who are purchasing tobacco or roll your own tobacco products; cannot distinguish between tax avoidance and tax evasion; results may reflect temporal bias in tax-based sales.10
Butt collections Simple and direct method; unobtrusive; avoids challenges of self-reported bias; similar collections over time may provide indications of trends in illicit consumption.Difficult to achieve a representative sample as contraband consumption may vary widely by population, location and time of collection; is challenging to accurately distinguishing legal from illegal butts; cannot distinguish between legal tax avoidance and illegal tax evasion.3
Pack swap surveys Relies on objective observational data (as opposed to self-reported data); similar surveys conducted over time may gauge trends.May be challenging, expensive and/or time consuming to achieve a representative sample; distinguishing between legal tax avoidance (such as duty-free purchases) and illegal tax evasion requires additional data (information from smokers or lab inspection) and specific expertise; respondents with more than one pack may swap legal pack, resulting in low estimates.3
  • Developed from Merriman,27 Reuter and Majmundat,28 Ross3 and Stratton et al.47

  • *Some studies used multiple methods.

  • ITTP, illicit trade in tobacco products.