Evaluation Reports

Section 5B of the ordinance that created the Sweetened Beverage Tax (Ordinance 125324) requires the City to work with academic researchers to assess the impact of the tax on the following:

  1. Economic outcomes (such as household food expenditures, beverage prices and sales, jobs, and store revenue)
  2. Health behaviors (such as food and beverage purchases and consumption)
  3. Intermediate health outcomes
  4. Identification and assessment of food deserts in the City
  5. Effectiveness and efficiency of the food bank network in the City.

The Seattle Office of the City Auditor is contracting with Public Health - Seattle & King County to complete a five-year evaluation of the Sweetened Beverage Tax (SBT). The SBT Evaluation Team includes academic researchers and public health practitioners. The Community Advisory Board also provides input on the design and implementation of the evaluation. 

Latest Sweetened Beverage Tax Evaluation Reports 

12-Month Report: Store Audits & Child Cohort | April 2020  
This report provides information about the impact of the Sweetened Beverage Tax on retail prices and consumption after one year of implementation. The researchers revisited stores where they collected baseline and 6-month information, and checked back in with families participating in a cohort study tracking consumption of sugary beverages over time. 

Summary Results from the Six-month Store Beverage Prices Report and the Healthy Food Availability & Food Bank Network Report (June 2019)

Read the report in Somali (af Soomaali)
The purpose of this report is to summarize results from two key studies of the Sweetened Beverage Tax Evaluation.

Healthy Food Availability & Food Bank Network Report | Slides (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 (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

Powell 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.
This research brief presents information on the estimated number of teaspoons (tsp) of daily added-sugar intake from sugary beverages and the frequency of sugary beverage consumption among adults aged 18-64 living in Seattle, WA, in 2017.