BACKGROUND: The availability of cheap illicit cigarettes (IC) may undermine the equity effect of cigarette excise tax policy in decreasing smoking prevalence, especially among vulnerable populations. Yet, only limited nationally representative data is available from LMICs, quantifying how much IC smoking influence more vulnerable cigarette smokers’ response to cigarette price increases.
METHODS: This study used data from the South African Global Adult Tobacco Survey 2021 (N=6,311 sample; n=1,327 current smokers) to assess smoking behaviours in response to hypothetical increase in cigarette prices, including smoking fewer cigarettes or attempting to quit smoking (price-responsive) as opposed to switching to cheaper brands or sourcing for a low cost for same brand (price-avoidance). A weighted estimate of IC prevalence was derived using a previously validated question on participants’ estimation of the proportion of cigarettes they have purchased that they considered ‘illicit’. The multivariable-adjusted binary logistic regression model examined the associations between IC use and being price-responsive, adjusting for sociodemographic factors. A decomposition analysis then quantified the extent to which IC use contributes to racial and rural-urban disparities in response to price increases.
RESULTS: IC prevalence was estimated to be 46.8% and IC users (aOR=0.68; 95%CI=0.53–0.89) and nicotine-dependent smokers (aOR=0.57; 95%CI=0.43–0.76) were less likely to be price-responsive as opposed to being price-avoiding in response. Rural residents had lower odds of being price-responsive (aOR=0.55; 95%CI=0.41-0.74) and as compared to others, black Africans were more likely to be price-responsive (aOR=2.05; 95%CI=1.43-2.94). Decomposition analysis suggests IC use mediates the effects of racial disparities (in favour of other race groups) on response to cigarette price increases by 6.5% and effect of the urban-rural gap by 5.7%, in favour of urban residents.
CONCLUSIONS: Even with high prevalence of illicit cigarettes, price increases will likely motivate reduced cigarette consumption among most smokers, but their equity impact is partially mitigated by illicit cigarette availability.