Studies suggest that taxes on American soft drinks work – but maybe not as well as hoped: The Salt: NPR

This week, the governor of Connecticut has proposed a national tax on sweetened beverages. Several cities have already introduced such soft drink taxes to raise money and fight obesity. And new evidence suggests that these taxes work – though sometimes worse than expected.

Kris Madsen, associate professor of public health at the University of California at Berkeley, is one of the researchers who study tax on sodas, particularly because she is convinced that sugary drinks constitute a threat to society, a direct cause of obesity.

"For public health, it is quite difficult to say that something is causing a major epidemic," she said. "We can do that for sugary drinks."

Berkeley was the first American city to tax these drinks, making them more expensive, and Madsen leads a team of researchers who are trying to see how the tax works.

"We have been going to the same neighborhoods every year for five years and we ask people the same questions," she says. Researchers interview people on the street, mostly in low-income neighborhoods.

They started doing it before the soft drink tax came into effect three years ago, and every year since.

"We have seen a 52% drop in consumption in the first three years" since the tax came into effect, she said. "It has a huge impact."

The Madsen study was published online this week by the American Journal of Public Health.

The memories, of course, are not completely reliable; moreover, it is possible that the people of Berkeley underestimate their consumption because they do not want to admit that they always drink a lot of soda.

At the same time, other researchers are attempting to quantify the impact of soft drink taxes by examining sales data from retail establishments, including grocery stores and convenience stores.

Anna Tuchman, of Northwestern University, is part of a group studying the tax on sodas in Philadelphia. The Philadelphia tax is different from that of Berkeley. It is larger and also covers beverages sweetened with both sugar and low calorie sweeteners. This is partly due to the fact that this tax is mainly aimed at collecting more money for schools and playgrounds.

Tuchman says that sales of these drinks in Philadelphia have fallen sharply by 46% since the tax came into effect.

But there is a problem. "We are seeing a very strong increase in sales of soda and other taxable goods in stores located between zero and four miles from the city," she says.

Basically, it seems like a lot of people in Philadelphia go to stores located just outside the city to buy their drinks. This is especially true in the case of sugary drinks; a little less artificially sweetened drinks. Taking this into account, sales in and around the city have dropped by about 20%, not by 46%. And the sales of sweetened drinks fell even less.

This is detrimental to the city's soda tax goals. "People are able to maintain their sugar and calorie intake, and the city is not able to raise tax revenue," says Tuchman.

Tuchman and his colleagues are still reviewing their document. it has not yet been officially reviewed by other scientists. At the present time, however, this shows some of the difficulties that cities face with their taxes on sodas.

There are also political obstacles. The soft drink industry has responded by saying that taxes on soft drinks are unfair to consumers and will not really improve people's health. In fact, the California legislature has recently strengthened the power to reluctantly adopt a moratorium on additional taxes on soft drinks imposed by cities in that state.

Oakland and San Francisco, however, have already implemented taxes on soft drinks, and Seattle has put in place one in early 2018.

Supporters of the soft drink tax, for their part, say that there is a simple way to prevent people from avoiding it by leaving the city: it is enough to adopt a tax that covers an entire state. – even a whole country.

In fact, Mexico introduced a tax on sweetened beverages in 2014. This tax is less important than US soft drink taxes and has a smaller impact on consumption. According to a study, the consumption of sugary drinks decreased by about 8% on average.