Silver et al. (2017) on the Berkeley Soda Tax

Lynn D. Silver, Shu Wen Ng, Suzanne Ryan-Ibarra, et al., “Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study.” PLoS Med 14(4), April 18, 2017, https://doi.org/10.1371/journal.pmed.1002283.

• Berkeley imposed a 1-cent per ounce tax for sugar-sweetened beverages starting in January, 2015; even before the tax, Berkeley per-capita soda consumption was quite low by US standards. 

• The study compares the before-and-after situation in Berkeley stores with comparable stores outside of Berkeley. 

• The tax led to higher soda prices in chain-stores, and to a significant fall in soda purchases, as well as a rise in water purchases. Consumers don’t seem to spend more on beverages after the tax is imposed. The overall effect on calories consumed is uncertain.