Evaluation of Seattle’s sweetened beverage tax on tax support and perceived economic and health impacts

It is important to understand whether the publics’ attitudes towards sugary beverage taxes (SBT) change after tax implementation to ensure the long-term success of tax policies. Seattle’s SBT went into effect on January 1, 2018. We administered a mixed-mode survey to adults in Seattle and comparison areas, pre- and 2-years post-tax, to evaluate the impact of the SBT on 1) tax support and 2) perceived tax impacts (N = 2,933). Using a difference-in-differences approach, we employed adjusted income-stratified modified Poisson models to test the impacts of the tax on net changes in attitudes in Seattle versus the comparison areas, pre- to post-tax. Among lower-income individuals in Seattle, support for the tax increased by 14% (PR(DD): 1.14; 95% CI: 1.08, 1.21) and there was a 20% net-increase in the perception that the SBT would positively affect the economy (PR(DD): 1.20; 95% CI: 1.05, 1.39), compared to changes in the comparison areas. Among higher-income individuals in Seattle, support for the tax was not different (PR(DD): 0.93; 95% CI: 0.70, 1.22) pre- to post-tax, but there was a net-increase in the perception that the tax would have negative effects on small businesses (PR(DD): 1.44; 95% CI: 1.03, 2.00) and family finances (PR(DD): 1.86; 95% CI: 1.09, 3.19). After living with the tax for 2-years, support for the tax increased among lower-income individuals in Seattle. Tax support was high and unchanged among higher-income individuals, but overall attitudes became more negative. Policy makers should consider investing in ongoing campaigns that explain the benefits of SSB taxes and revenues.