Abstract
Sugar-sweetened beverage (SSB) excise taxes are promoted as a key policy to reduce cardiometabolic diseases and other conditions, but comprehensive analyses of US SSB taxes have been difficult due to the absence of suitable methodologies to account for confounding factors. We use recent advances in synthetic control methods to estimate the changes in SSB prices and purchases in five large cities in the US in the two years following their respective implementation of SSB taxes. We find prices of SSB products increased by an average of 33.1% over the 2 years following tax implementation, corresponding to an average price increase of 1.3 cents per ounce and a price pass-through rate of 92% from distributors to consumers. SSB purchases in total volume declined by an average of 33.0%, corresponding to a price elasticity of demand of -1.00. The observed price increase and corresponding volume decrease immediately followed tax implementation, and both were sustained in the months thereafter. We also assessed changes in adjacent, untaxed areas to detect any increase in cross-border purchases, finding no evidence of increased cross-border purchases following tax implementation. Relating our findings to the medical literature suggests that SSB taxation would likely generate significant improvements in population health and large cost-savings, which would apply across a diverse set of demographic and geographic settings.
