Division of Health Policy and Administration, School of Public Health, University of Illinois at Chicago, Chicago, IL, United States.
Institute for Health Research and Policy, University of Illinois at Chicago, Chicago, IL, United States.
Econ Hum Biol. 2020 May;37:100856. doi: 10.1016/j.ehb.2020.100856. Epub 2020 Jan 21.
On January 1, 2018 the city of Seattle, WA, implemented a 1.75-cent per ounce (oz) Sweetened Beverage Tax (SBT) on sugar-sweetened beverages with at least 40 calories per 12 oz. This study drew on universal product code-level store scanner data and used a pre-post intervention-comparison site difference-in-differences (DID) study design to assess the impact of the SBT on taxed beverage prices in Seattle, the volume sold of taxed beverages in Seattle and in its 2-mile border area (cross-border shopping), and the volume sold of untaxed beverages (substitution) relative to changes in its comparison site of Portland, OR. The DID results showed that, on average, in the first year post-tax implementation, prices of taxed beverages rose by 1.03 cents per oz (p < 0.001) corresponding to a 59% tax pass-through rate. Volume sold of taxed beverages fell, on average, by 22% (p < 0.001) in the first year following the implementation of the tax. Volume sold of taxed beverages fell to a greater extent for family- versus individual-size beverages (31% versus 10%) and fell to a greater extent for soda (29%) compared to all other beverage types. Moderate substitution to untaxed beverages was found - volume sold of untaxed beverages increased by 4% (p < 0.05). The results revealed no significant increases in the overall volume sold of taxed beverages in the 2-mile border area of Seattle relative to its comparison site suggesting that tax avoidance in the form of cross-border shopping did not dampen the impact of the tax.
2018 年 1 月 1 日，华盛顿州西雅图市对每盎司含糖量至少为 40 卡路里的含糖饮料征收 1.75 美分的甜味饮料税。本研究利用通用产品代码级别的商店扫描数据，采用前后干预对照点差异（DID）研究设计，评估了 SBT 对西雅图征税饮料价格、西雅图及其 2 英里边境地区（跨境购物）销售的征税饮料量以及未征税饮料（替代）销售量的影响，与俄勒冈州波特兰市（对照点）的变化相比。DID 结果表明，平均而言，在征税实施后的第一年，征税饮料的价格上涨了 1.03 美分/盎司（p < 0.001），对应 59%的税收转嫁给消费者。征税饮料的销售量平均下降了 22%（p < 0.001），在征税实施后的第一年。家庭装和个人装的征税饮料销售量下降幅度更大（31%比 10%），苏打水（29%）比其他所有饮料类型下降幅度更大。发现了适度的向未征税饮料的替代——未征税饮料的销售量增加了 4%（p < 0.05）。结果显示，西雅图 2 英里边境地区征税饮料的总销售量与对照点相比没有显著增加，这表明以跨境购物形式的避税并没有削弱税收的影响。
