K A S H R U T . C O M_©

After years of inconclusive data, new evidence suggests that Seattle’s soda tax is working—and it’s working really well

December 16, 2021 from The Food Dive:

"Armed with three years of grocery shopping data, researchers found that total sugar sales are down by almost 20 percent, driven largely by falling soda purchases.

"In a recent analysis, researchers used a large set of grocery shopping data to track food and drink sales before and after the city of Seattle implemented a sugary drinks tax in January of 2018. The data set itself—gathered by marketing insight firm Nielsen—was huge, representing 45 percent of all food store sales in the city for 2017, 2018, and 2019. To create a control group, researchers also obtained the same data for the nearby city of Portland, Oregon, which doesn’t have a sugary drinks tax in place.

"To account for different sugar levels in various beverages, a team led by Lisa Powell, health policy professor at the University of Illinois at Chicago, coded each type of drink by its exact sugar content. In doing so, they found that the total amount of sugar sold through taxed drinks dropped by 23 percent in Seattle compared to sales of the same products in Portland, one year after the implementation of the soda tax. That decline held for the following year as well, suggesting that the dip was not just a fluke.

"But the researchers didn’t stop there. They also wanted to know if shoppers might be getting sugar from other foods instead—a possibility that soda tax opponents have argued would become commonplace. Were Seattle residents simply swapping out Mountain Dew for candy bars? To find out, the researchers also analyzed sales data for untaxed drinks like flavored milk, sweets—which the team defined to include candies, desserts, and baked goods—as well as loose sugar. Over the course of months, Powell’s team painstakingly coded each product sold by its sugar content, and then calculated just how much sales of these products changed after the soda tax went in place.

"They found a slight increase in sugar consumed through untaxed drinks in 2018, which then dissipated in 2019. They also noticed a small, sustained increase in sugar consumed through sweets. In both cases however, those upticks were not large enough to overcome the significant reduction in sugar sold through taxed drinks.

"The findings bolster the city of Seattle’s own early findings about the effectiveness of the soda tax. Last year, researchers at the University of Washington found that low-income families in particular saw a significant decrease in soda consumption following the implementation of the tax. The findings were based on a survey of residents, meaning that it relied on self-reporting, which is less accurate than sales data. However, self-reported numbers play a crucial role in capturing soda sales outside of grocery stores, such as at restaurants and bars, which were not included in Powell’s study.

"The results may have promising public health implications. Almost 60 percent of Americans exceed the Dietary Guidelines’s suggested limit on added sugar consumption. This can contribute to health issues including diabetes and heart disease, making eaters more vulnerable to diseases and more likely to incur higher healthcare costs over the course of their lives.

"Whether these findings might compel other cities to adopt similar policies is still an open question. In response to growing support for soda taxes, food and drink lobby groups have pushed back forcefully to curtail their implementation through a political strategy known as “preemption.” Pioneered by the tobacco industry in the 1970s, this involves lobbying for state-level lawmaking that prevents local jurisdictions from adopting their own public health ordinances.

"And that’s exactly what happened in Washington shortly after Seattle passed its soda tax: In November of that same year, soda companies campaigned successfully for the passage of a ballot initiative banning all future fees on sugary drinks across the state. If Seattle’s neighbors want to pass their own soda taxes, they’ll have to wait for its repeal."