Research Unit on the Economics of Excisable Products (REEP), School of Economics, University of Cape Town, Cape Town, Western Cape, South Africa
Research Unit on the Economics of Excisable Products (REEP), School of Economics, University of Cape Town, Cape Town, Western Cape, South Africa.
BMJ Open. 2023 Aug 1;13(8):e072538. doi: 10.1136/bmjopen-2023-072538.
To estimate the own-price, cross-price and income elasticities for carbonated soft drinks (CSDs), malt drinks, chocolate powder, sachet water and sugar in Nigeria. These elasticities can be used to estimate the potential demand response to the recently-introduced sugar tax in Nigeria.
The study uses household data from the 2018/2019 Nigeria Living Standards Survey (NLSS).
The NLSS is a national household survey. 21 114 households were included in the final sample for this analysis.
We used Deaton's almost ideal demand system, which controls for the goods' quality, to estimate the effect of price and income changes on the demand for CSDs, chocolate powder, malt drinks, sachet water and sugar.
We found that the own-price elasticity (ordered from most to least price-responsive) was -0.99 (p<0.01) for sachet water, -0.76 (p<0.01) for CSDs, -0.72 (p<0.01) for chocolate powder, -0.62 (p<0.01) for sugar and -0.19 (p<0.01) for malt drinks. The cross-price elasticities indicate that malt drinks and chocolate powders are substitutes of CSDs. The income elasticities indicate that all the commodities are normal goods. Sachet water had the highest income elasticity at 0.62 (p<0.01), followed by chocolate powder at 0.54 (p<0.01), CSDs at 0.47 (p<0.01), malt drinks at 0.43 (p<0.01) and sugar at 0.13 (p<0.01).
Even though the price elasticities for CSDs, malt drinks and chocolate powder are less than one, in absolute terms, they are significantly different from zero. Increases in the sugar-sweetened beverage tax could curb the demand for these beverages, and, in turn, reduce the incidence and prevalence of sugar-attributable diseases.
估计尼日利亚碳酸软饮料（CSD）、麦芽饮料、巧克力粉、袋装水和糖的自价格、交叉价格和收入弹性。这些弹性可用于估计对尼日利亚最近引入的糖税的潜在需求反应。
本研究使用 2018/2019 年尼日利亚生活水平调查（NLSS）的家庭数据。
NLSS 是一项全国性的家庭调查。最终样本中包含 21114 户家庭。
我们使用 Deaton 的几乎理想需求系统，该系统控制了商品的质量，以估计价格和收入变化对 CSD、巧克力粉、麦芽饮料、袋装水和糖需求的影响。
我们发现，自价格弹性（按对价格最敏感的顺序排列）为：袋装水-0.99（p<0.01），CSD-0.76（p<0.01），巧克力粉-0.72（p<0.01），糖-0.62（p<0.01）和麦芽饮料-0.19（p<0.01）。交叉价格弹性表明，麦芽饮料和巧克力粉是 CSD 的替代品。收入弹性表明，所有商品都是正常商品。袋装水的收入弹性最高，为 0.62（p<0.01），其次是巧克力粉 0.54（p<0.01），CSD 为 0.47（p<0.01），麦芽饮料为 0.43（p<0.01），糖为 0.13（p<0.01）。
尽管 CSD、麦芽饮料和巧克力粉的价格弹性小于 1，但绝对值上与零显著不同。增加含糖饮料税可能会抑制这些饮料的需求，从而降低与糖相关的疾病的发病率和流行率。
