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.

中文翻译：

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西雅图的甜饮料税对饮料价格和销量的影响。

2018年1月1日，华盛顿州西雅图市对含糖饮料（每12盎司至少40卡路里）征收1.75美分/盎司（盎司）的甜饮料税（SBT）。这项研究借鉴了通用产品代码级商店扫描仪数据，并使用了事前干预比较站点间差异（DID）研究设计，以评估SBT对西雅图的含税饮料价格，销售量的影响。西雅图及其2英里边界区域（跨境购物）中的含税饮料，以及相对于俄勒冈州波特兰市比较地点的变化而言，无税饮料的销量（替代品）。DID结果显示，在实施税后的第一年，应税饮料的平均价格每盎司上涨1.03美分（p <0.001），相当于59％的税收通过率。含税饮料的销售量下降，实施税收后的第一年平均增加22％（p <0.001）。与所有其他类型的饮料相比，家庭大小饮料的征税饮料销量下降幅度较大（分别为31％和10％），苏打水的销量下降幅度更大（29％）。发现对无税饮料的替代程度适中-无税饮料的销量增加了4％（p <0.05）。结果显示，与西雅图的比较地点相比，西雅图2英里边界地区的应税饮料总销量没有明显增加，这表明以跨境购物的形式进行避税并不会削弱税收的影响。与所有其他类型的饮料相比，家庭大小饮料的征税饮料销量下降幅度较大（分别为31％和10％），苏打水的销量下降幅度更大（29％）。发现对无税饮料的替代程度适中-无税饮料的销量增加了4％（p <0.05）。结果显示，与西雅图的比较地点相比，西雅图2英里边界地区的应税饮料总销量没有显着增加，这表明以跨境购物形式进行的避税并不会削弱税收的影响。与所有其他类型的饮料相比，家庭大小饮料的征税饮料销量下降幅度较大（分别为31％和10％），苏打水的销量下降幅度更大（29％）。发现对无税饮料的替代程度适中-无税饮料的销量增加了4％（p <0.05）。结果显示，与西雅图的比较地点相比，西雅图2英里边界地区的应税饮料总销量没有明显增加，这表明以跨境购物的形式进行避税并不会削弱税收的影响。