In 2016's Impact of the Berkeley Excise Tax on
Sugar-Sweetened Beverage Consumption (Sci-Hub Onion mirror), UC Berkeley scientists showed that the imposition of a $0.01/ounce tax on sugary drinks led to a sharp decrease in the consumption of sodas in Berkeley.
Anaecdotal evidence from other territories that have tried "sugar taxes" show similar outcomes: Bloomberg says that Philadelphia shopkeepers self-report a 50% drop-off in sugary drink sales after a similar tax came into effect there. A formal study in Mexico upholds the finding.
There is no data yet on what effect, if any, this has on health issues related to sugar consumption, including obesity.
Health groups, like the American Heart Association, support the tax as a way to reduce sugar intake, but there's a catch: the soda tax in both Berkeley and Philadelphia is imposed on distributors, not as a sales tax to consumers. People begin drinking less soda once the tax is passed on in the form of higher prices in stores and on menus — but theres a risk that grocery stores and restaurants may choose to increase prices on other products instead.
Impact of the Berkeley Excise Tax on
Sugar-Sweetened Beverage Consumption [Jennifer Falbe, Hannah R. Thompson, Christina M. Becker, Nadia Rojas, Charles E. McCulloch, and Kristine A. Madsen/Journal of Public Health] [Sci-Hub mirror (requires Tor Browser)]
It Turns Out That Taxing Soda Makes People Drink Less Soda
(Image: A view of Sugar, Parvathisri, CC-BY-SA)