Annual 10% tax increases from 2011 to 2025
 Tobacco excise tax increasesAnnual increase of 10% (above annual inflation). A level of tax passthrough of 100% was assumed.Uncertainty:±10% (or 1% point of 10% excise tax) SD, normal distribution.
In scenario analyses, we also analysed the potential impact of 20% tobacco tax increases until 2025.
 Illicit tobacco market dynamicsThe illicit market was set to start at 1% of the market share (based on recent New Zealand (NZ) work32). The growth in the illicit market was tied to the size of the yearly increase in the price of tobacco, with every 10% increase in the legal price of a pack of 20 cigarettes equating to a 1% increase in the illicit market. The average tobacco price used in the modelling was a combined function of the legal market price of tobacco, the illicit price of tobacco (75% of the legal price which we estimated from Australian work in the absence of NZ data)33 and the size of the illicit market.Uncertainty of ±20% SD, beta distribution, around the illicit price of tobacco.
In scenario analyses, we set the market share of the illicit market to remain at 1% (ie, a stable illicit market).
 Age-varying tobacco price elasticities (prevalence) Non-Māori: Price elasticities of −0.38 (for 20 year olds), −0.29 (for 21–24 year olds), −0.19 (for 25–24 year olds) and −0.10 (for 35+ year old) for tobacco smoking prevalence applied in the year of the tax increase. These price elasticities for tobacco smoking prevalence were also used in other NZ tobacco tax modelling work.11
Māori: The aforementioned price elasticities were scaled up by 20%, given economic theory, international evidence on increased price sensitivity in other social groupings and NZ evidence for increased price sensitivity among Māori.34 35
Uncertainty: non-Māori, ±20% SD, normal, correlated 1.0 across the four age groups; Māori absolute scalar of +20% within each of the four age groups, ±10 percentage points.
(95% UI: 0.4% to 39.6% higher price elasticities among Māori compared with non-Māori)
In scenario analyses, we applied the same age-varying price elasticities to Māori and non-Māori.