Soda taxes—though they actually apply to other sugary drinks as well—have proven controversial, to say the least.
There’s no national soda tax in the United States, but also nothing to stop individual localities from instituting their own. Some have been passed and then repealed, some remain on the books, and some have failed at the ballot box, but one question appears to have been answered: do they actually work?
The category of drink to which these taxes apply is usually referred to as “sugar-sweetened beverages,” or SSBs. Those include non-diet sodas as well as energy drinks, sports drinks, and some not-so-fruity fruit juices. Focusing on just the USA, many cities have imposed a tax. Philadelphia has one at three cents per ounce, and many other cities—Seattle, Portland, Boulder, San Francisco, Berkeley, Oakland—have taxes ranging from one cent per ounce to two. New York City attempted to flat-out ban sodas above a certain size, though that ban was eventually struck down. Chicago, too, had a tax briefly, though it was eventually repealed.
A new survey from the University of Otago, in New Zealand, looked at over a thousand studies concerning four American cities with the tax (Philadelphia; Portland, ME; Berkeley; and Cleveland), along with a few international locales (Catalonia, Spain; and the entire countries of Mexico, Chile, and France, which have nationwide taxes) to see how effective it really was. The studies examined by the researchers included a wide variety of subjects: purchasing habits before and after the tax, overall sales, and the sales of non-taxed drinks like water.
The researchers found that the tax is, across the board, effective, with a 10 percent tax resulting in about 10 percent less consumption of sugary drinks. There was also about a two percent uptick in the purchase of non-taxed beverages, especially water. They do note that many studies did not examine socioeconomic status, an important variable in any public health review. But overall, the researchers are confident in their conclusion that a tax on sugary drinks results in a decrease in consumption.
There are other debates to be had about taxes like this; the soda companies and some libertarian-leaning politicians harp on the restriction of purchasing freedom. But the study is important in taking one playing piece off the table: the question of whether the taxes actually work. It seems they do.