Guindon G Emmanuel, Abbas Umaima, Trivedi Riya, Garasia Sophiya, Johnson Sydney, John Rijo M
Centre for Health Economics and Policy Analysis, McMaster University, Hamilton, Ontario, Canada.
Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.
PLOS Glob Public Health. 2023 Sep 27;3(9):e0002342. doi: 10.1371/journal.pgph.0002342. eCollection 2023.
There is indisputable evidence that increases in taxes that raise tobacco prices reduce tobacco use. Consumption taxes on manufactured tobacco products, however, can be regressive in socioeconomic status (e.g., when the ratio of tax paid to income is lower for higher-income groups than for lower-income groups). Nevertheless, if the poor or less educated are more price responsive, a change in tobacco tax may be progressive in socioeconomic status. Existing reviews clearly indicate that populations with lower income or education are more responsive to tobacco tax and price changes than higher-income and more educated populations in high-income countries. Research pertaining to low- and middle-income countries was, however, limited and inconclusive. We conducted a review of quantitative studies that examined if socioeconomic status modified the association between prices and taxes and tobacco use in low- and middle-income countries. We searched two electronic databases, two search engines, and two working paper repositories. At least two reviewers independently screened articles for inclusion, extracted detailed characteristics, and assessed the risk of bias of each included study. Thirty-two studies met our inclusion criteria. Overall, we found that the evidence in low- and middle-income countries was too limited and methodologically weak to make any conclusive statements. Our review highlights a number of data and methodological limitations in existing studies. The most important limitation was the lack of formal assessment of socioeconomic differences in price responsiveness. Only seven of 32 studies assessed statistically whether own-price effects were modified by socioeconomic status. Many modelling studies have examined the distributional effect of a tax increase on tobacco use, while assuming a strong own-price elasticity gradient in income. The poor were generally assumed to be more responsive to price by a factor of two to five, relative to the wealthy. Although there are theoretical reasons to expect poorer individuals to be more responsive to monetary prices than wealthy ones in low- and middle-income countries, our review provides little empirical support.
有确凿证据表明，提高烟草价格的税收增加会减少烟草使用。然而，对制成烟草产品征收消费税在社会经济地位方面可能具有累退性（例如，当高收入群体支付的税款与收入之比低于低收入群体时）。尽管如此，如果穷人或受教育程度较低者对价格变化更敏感，烟草税的变化在社会经济地位方面可能具有累进性。现有综述清楚地表明，在高收入国家，收入或教育程度较低的人群比高收入和受教育程度较高的人群对烟草税和价格变化更敏感。然而，与低收入和中等收入国家相关的研究有限且无定论。我们对定量研究进行了综述，这些研究探讨了社会经济地位是否改变了低收入和中等收入国家价格、税收与烟草使用之间的关联。我们检索了两个电子数据库、两个搜索引擎和两个工作论文库。至少两名评审员独立筛选文章以确定是否纳入，提取详细特征，并评估每项纳入研究的偏倚风险。32项研究符合我们的纳入标准。总体而言，我们发现低收入和中等收入国家的证据过于有限且方法薄弱，无法得出任何确凿结论。我们的综述突出了现有研究中的一些数据和方法局限性。最重要的局限性是缺乏对价格敏感度社会经济差异的正式评估。32项研究中只有7项从统计学上评估了自价格效应是否因社会经济地位而改变。许多模型研究在假设收入方面存在很强的自价格弹性梯度的同时，研究了增税对烟草使用的分配效应。一般认为，相对于富人，穷人对价格的敏感度通常高出两到五倍。尽管有理论依据预期在低收入和中等收入国家较贫困个体对货币价格的敏感度高于富裕个体，但我们的综述几乎没有提供实证支持。
