A study published in PLOS Medicine suggests that a tax on sugar-sweetened beverages (SSBs) may cause sales of SSBs to decline and sales of untaxed beverages and water to increase. The researchers set out to examine the association of the first penny-per-ounce SSB excise tax in the United States (specifically, in Berkeley, Calif.) with beverage prices, sales, store revenue/consumer spending, and usual beverage intake.
The researchers compared the following data both before the tax was implemented (before January 1, 2015) and after the first year of the tax (March 1, 2015–February 29, 2016):
Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce), beverage sales (ounces), consumers’ spending measured as store revenue (inflation-adjusted dollars per transaction) in two large chains, and usual beverage intake (grams/day and kilocalories/day).
The researchers found that after one year with the tax, SSB sales (ounces/transaction) in Berkeley stores declined 9.6% compared to estimates if the tax were not in place, but rose 6.9% for non-Berkeley stores. In addition, sales of untaxed beverages in Berkeley stores rose by 3.5% versus 0.5% for non-Berkeley stores. Overall beverage sales also rose across stores. In Berkeley, sales of water rose by 15.6% (exceeding the decline in SSB sales in ounces); untaxed fruit, vegetable, and tea drinks, by 4.37%; and plain milk, by 0.63%. They also found that overall consumer spending per transaction in the stores studied did not rise.
“Significant declines in SSB sales, even in this relatively affluent community, accompanied by revenue used for prevention suggest promise for this policy,” wrote the researchers. “Evaluation of taxation in jurisdictions with more typical SSB consumption, with controls, is needed to assess broader dietary and potential health impacts.”