Department of Health Systems Science, University of Illinois at Chicago College of Nursing, Chicago, Illinois.
Institute for Health Research and Policy, University of Illinois at Chicago, Chicago, Illinois.
Am J Prev Med. 2020 May;58(5):648-656. doi: 10.1016/j.amepre.2019.12.014. Epub 2020 Mar 16.
In July 2017, Oakland, California implemented a 1 cent/ounce sugar-sweetened beverage tax. This study examined changes in store marketing practices-advertising and price promotions-for sugar-sweetened beverages, artificially sweetened beverages, and unsweetened beverages following the introduction of the tax.
The study employed a quasi-experimental research design and included Oakland as the intervention site and Sacramento, California as a comparison site. Based on data collected pretax (May-June 2017), 6 months post-tax (January 2018), and 12 months post-tax (June 2018) at 249 stores across the 2 sites, exterior and interior advertising for 4 taxed sugar-sweetened beverage subtypes and 6 untaxed artificially sweetened and unsweetened beverage subtypes, as well as price promotions for 59 specific taxed products and 69 untaxed products were examined. In 2019, difference-in-differences logistic regressions estimated pre-post changes in Oakland relative to Sacramento.
At 6 months post-tax, the odds of sugar-sweetened beverage price promotions fell 50% in Oakland but only 22% in Sacramento. Price promotions for regular soda in particular declined in Oakland post-tax, by 47% at 6 months and 39% at 12 months (versus no change in Sacramento). Moreover, the odds of artificially sweetened beverage price promotions fell by a similar magnitude as sugar-sweetened beverages in Oakland, 55% at 6 months and 53% at 12 months, which differed significantly from Sacramento. No significant post-tax changes were found in sugar-sweetened or artificially sweetened beverage exterior or interior advertising.
Rather than increasing marketing, retailers and manufacturers may have tried to offset revenue losses by reducing price promotions for sugar-sweetened beverages, particularly regular soda, and artificially sweetened beverages.
2017 年 7 月，加利福尼亚州奥克兰市实施了每盎司 1 美分的含糖饮料税。本研究旨在调查该税种实施后，商店对含糖饮料、人工甜味饮料和无糖饮料的营销实践（广告和价格促销）的变化。
该研究采用了准实验研究设计，以奥克兰为干预点，加利福尼亚州萨克拉门托为对照点。基于税收前（2017 年 5 月至 6 月）、税收后 6 个月（2018 年 1 月）和税收后 12 个月（2018 年 6 月）在两个地点的 249 家商店收集的数据，对 4 种征税的含糖饮料和 6 种未征税的人工甜味和无糖饮料的外部和内部广告以及 59 种特定征税产品和 69 种未征税产品的价格促销情况进行了检查。2019 年，采用差值差异逻辑回归估计了奥克兰相对于萨克拉门托的税收前后变化。
税收后 6 个月，奥克兰含糖饮料价格促销的可能性下降了 50%，而萨克拉门托仅下降了 22%。特别是奥克兰的普通苏打水的价格促销在税收后下降了 47%，在 6 个月和 12 个月时分别下降了 39%（而萨克拉门托没有变化）。此外，奥克兰人工甜味饮料价格促销的可能性下降幅度与含糖饮料相似，税收后 6 个月下降了 55%，12 个月下降了 53%，与萨克拉门托有显著差异。税收前后，含糖饮料和人工甜味饮料的外部或内部广告均未出现显著变化。
零售商和制造商可能试图通过减少含糖饮料（特别是普通苏打水）和人工甜味饮料的价格促销来抵消收入损失，而不是增加营销。
