Impact on Smoking Behavior of the New Zealand Annual Increase in Tobacco Tax: Data for the Fifth and Sixth Year of Increases.

Introduction: New Zealand has implemented a series of seven annual increases in tobacco tax since 2010. All tax increases, except for the first in the series, were preannounced. It is unusual for governments to introduce small, persistent, and predictable increases in tobacco tax, and little is known about the impact of such a strategy. This paper evaluates the impact of the fifth and sixth annual increases.

Methods: Smokers' behaviors were self-reported during the 3-month period before, and the 3-month period after, the two annual increases. Responses to the two increases were analyzed separately, and generalized estimating equations models were used to control for sociodemographic variables, recent quit attempts, and the research design.

Results: Findings were consistent across years. The proportion of participants who made a smoking-related (54%-56% before and after each tax increase) or product-related change (fifth tax increase: 17%-19%; sixth tax increase: 21%-22%) did not significantly alter from before to after each tax increase. However, it should be noted that the proportion of participants making smoking-related changes was generally high, even prior to each increase. For example, before the 2015 tax increase, 1% reported quitting completely, 21% trying to quit, and 53% cutting down.

Conclusions: In New Zealand, with its series of annual tobacco tax increases since 2010, there were no significant changes in smoking- or product-related behavior associated with the fifth and sixth increases. Nevertheless, overall cessation-related activity was high, with a majority of participants reporting either quitting and/or cutting down recently.

Implications: Little is known about the impact of small, persistent, predictable tobacco tax increases on smoking behavior. This study evaluated the impact of the fifth (in 2014) and sixth (2015) tax increases in an annual series implemented in New Zealand. Although there were no detectable changes in smoking behaviors from before to after each tax increase, self-reported cessation-related activity was high overall (i.e., even prior to each increase). Given that there are multiple possible interpretations for these findings, more in-depth time-series analyses are needed to understand how such a tax strategy influences smoking behavior.