Evaluation Reports
Section 5B of the ordinance that created the Seattle Sweetened Beverage Tax (Ordinance 125324) requires the City to work with academic researchers to conduct a series of evaluations of the tax's effect on health and economic outcomes. The Seattle Office of the City Auditor is contracting with Public Health - Seattle & King County to lead the evaluations with a team that includes academic researchers and public health practitioners. The Sweetened Beverage Tax Community Advisory Board also provides input on certain parts of the evaluation.
Latest Sweetened Beverage Tax Evaluation Reports
Report on Norms and Attitudes Toward the Sweetened Beverage Tax 24 Months After the Tax's Implementation | FAQs (August 2021)
The Sweetened Beverage Tax Evaluation team undertook this norms and attitudes study to understand what Seattle-area adults believe about Seattle's Sweetened Beverage Tax and sugary beverages, and how those thoughts may have changed over the course of two years. This new report provides follow-up data on what the research team learned about norms and attitudes found in its 2018 baseline report, which was done before implementation of the Sweetened Beverage Tax.
12-Month Report: Store Audits & Child Cohort (April 2020)
This report summarizes findings from data collected 12 months after implementation of the Seattle Sweetened Beverage Tax on the price of beverages in stores and the beverage consumption of a cohort of lower-income children and parents living in Seattle and the South King County area.
Healthy Food Availability & Food Bank Network Report | Slides | Summary Report | Summary Report in Somali (February 2019)
This report begins with a literature review of the different ways to define and measure food access. Section 2 identifies Healthy Food Priority Areas in Seattle based on areas of the city with higher poverty rates, longer travel times to healthy food retailers, and greater density of unhealthy food retailers. Section 3 reports on the price and availability of healthy food in Seattle stores. Section 4 describes who experiences food insecurity in Seattle and who falls in the "food security gap". Finally, Section 5 assesses the food bank network in Seattle.
Six-month Store Beverage Prices Report | Slides | FAQs | Summary Report | Summary Report in Somali (January 2019)
Seattle's Sweetened Beverage Tax is a tax on the distributors of sugary beverages. However, a key evaluation question is whether the tax is passed on to consumers via higher retail prices. This report presents findings on beverage prices six months after the tax began compared to the baseline (pre-tax) prices.
Baseline Report: Evaluation of Seattle's Sweetened Beverage Tax | Slides (August 2018)
This report describes findings from the baseline (pre-tax) evaluation studies that required data collection in both Seattle and the comparison areas before the tax went into effect in January 2018. The study components include 1) store surveys to collect baseline beverage price data, 2) surveys of beverage consumption among a cohort of children and parents, 3) surveys of norms and attitudes about a sugary beverage tax, and 4) interviews and focus groups about perceptions of the sugar-sweetened beverages and implementation of the tax.
Other Research and Publications on Seattle's Sweetened Beverage Tax
Powell, L. Evidence of the Impacts of the Seattle Sweetened Beverage Tax. Presentation to the University of Washingon and City of Seattle. September 22, 2022.
Jones-Smith JC, Knox M, Coe NB, et al. Sweetened beverage taxes: Economic benefits and costs according to household income. Food Policy. 2022 July, Volume 110.
Powell, LM, Leider J. An Overview of the Impact of the Seattle, Washington, Sweetened Beverage Tax on Prices, Demand, Substitution, and Sugar Sold. Research Brief No. 124.
Powell LM, Leider J. Impact of a sugar-sweetened beverage tax two-year post-tax implementation in Seattle, Washington, United States. J Public Health Policy. 2021 Dec;42(4):574-588.
Powell LM, Leider J. The impact of Seattle's Sweetened Beverage Tax on beverage prices and volume sold. Econ Hum Biol. 2020 May;37:100856.
Oddo VM, Krieger J, Knox M, et al. Perceptions of the possible health and economic impacts of Seattle's sugary beverage tax. BMC Public Health. 2019;19(1):910.
Powell LM et al. Intake of Sugar-sweetened Beverages among Adults in Seattle, WA, 2017. Research Brief No. 106. Illinois Prevention Research Center, University of Illinois at Chicago. Chicago, IL. November 2018.