Per Steven Ross Johnson in US News “How ‘Soda Taxes’ Could Fuel Better Health”.

“In an analysis published in JAMA Health Forum, researchers examined changes in the prices and purchases of sugary drinks sold in retail stores in Boulder, Colorado; Philadelphia; Oakland, California; San Francisco; and Seattle from 2012 to 2020. Excise taxes on sugar-sweetened beverages were implemented in Boulder, Oakland and Philadelphia in 2017, according to the study, and in San Francisco and Seattle in 2018, with amounts ranging from 1 cent to 2 cents per ounce.

Researchers calculated that the prices of these drinks rose by an overall average of 33% in those cities in the two years after the taxes went into effect, or by 1.3 cents per ounce. Meanwhile, the volume in ounces of sugary drinks purchased during the same period decreased by 33%."

This study showed that with the soda tax, prices went up by 33% and sales dropped by the same….33%. The ill effects of sugar is well known and it shows tht the tax did have some effect in reducing consumption of these sugary drinks.