Residents of five U.S. cities reduced their consumption of sugar-sweetened beverages (SSB) by an average 33 percent following imposition of so-called soda taxes, said researchers who studied years of sales data. “Scaling SSB excise taxes across the United States would likely generate significant population health benefits and medical cost savings,” said the researchers in the journal JAMA Health Forum.
The study buttressed the arguments of soda-tax advocates—that higher prices would discourage consumption of sugary drinks that are linked to obesity and chronic disease such as diabetes. The World Health Organization recommends limiting sugar to less than 10 percent of daily calories and ideally less than 5 percent.
However, the impetus for SSB taxes waned years ago. Berkeley, California, was the first city, in 2015, to implement a soda tax, set at 1 cent per ounce. By November 2022, eight U.S. jurisdictions and 50 countries had implemented SSB taxes of some form, said the study in JAMA Health Forum. The team of six researchers assessed the results of soda taxes in Boulder, Colorado; Philadelphia, Pennsylvania; Oakland, California; Seattle, Washington; and San Francisco, California.
“Prices of SSBs increased by an average of 33.1 percent … during the two years following tax implementation, corresponding to an average price increase of 1.3 cents per ounce. SSB purchases declined by an average of 33.0 percent,” said the study. “SSB purchases declined in total volume by an average of 33.0 percent.
“The observed price increase and corresponding volume decrease immediately followed tax implementation, and both outcomes were sustained in the months thereafter. No evidence of increased cross-border purchases following tax implementation was found.”
For their work, researchers classified 5,500 Universal Product Codes as SSB and their sample included 26,338 stores; 496 of them in the cities with SSB taxes, 1,340 in neighboring cities, and 24,502 in a “donor pool.”
The study was one of the first to look at the effects of SSB taxes in more than one city. “These results help answer the critical question of how much variation across taxed localities is due to the unique characteristics of a locality vs. the generalizable outcomes of a tax,” said the researchers. “Several studies have found that a 15 percent to 20 percent increase in price/decrease in consumption generates significant health benefits, including reductions in myocardial infarction events, ischemic heart disease, coronary health events, strokes, diabetes, and obesity.”
The American Beverage Association says SSB taxes are unproductive and hurt consumers, reported NPR. “The calories that people get from beverages has decreased to its lowest level in decades,” trade group said in a statement to NPR.
Scott Kaplan, an economist at the U.S. Naval Academy, was lead author of the study. The first co-authors were from the United States and Canada.
The study, “Changes in prices and purchases following implementation of sugar-sweetened beverage taxes,” is available here.