Associations between the Sweetened Beverage Tax Implementation in Seattle, WA and Changes in Supermarket Interior Marketing Displays

Nicole Asa | 2022

Advisor: Jessica Jones-Smith

Research Area(s): Cardiovascular & Metabolic Disease, Nutritional Epidemiology

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Sugar-sweetened beverages (SSBs) are a significant contributor to added sugar intake, leading to implementation of sugar beverage taxes. SSB taxes may impact supermarket in-store marketing strategies, leaning either towards or away from taxed beverages. Our study aims to evaluate the changes in supermarket interior marketing displays one year after the implementation of Seattleā€™s Sweetened Beverage Tax, which went into effect January 1, 2018. This study used a quasi-experimental design with supermarkets in Seattle exposed to the tax, while supermarkets in a comparison area were unexposed. The outcome evaluated was number of SSB and non-SSB interior marketing displays at supermarkets before and after-tax implementation. We used Poisson regression difference-in-difference (DID) models to estimate the degree to which the interior marketing displays in Seattle change above and beyond the interior marketing displays in the comparison area. We found a decrease in average change of interior marketing displays for soda (DID= 0.80, 95%CI= 0.66, 0.98) and diet soda (DID= 0.74, 95%CI= 0.60, 0.91), and an increase for diet energy drinks (DID= 1.93, 95%CI: 1.11, 3.36). This evaluation found no significant changes in collective SSB and non-SSB interior marketing displays. There was little evidence supermarkets increased or decreased the number of interior marketing displays in response to the SSB tax.