Is a Soda Tax a Good Idea?
In today's Econundrum, Maddie Oatman argues in favor of taxing soda. She points out the scary amounts of calories that people consume in the form of sweetened beverages—and the mounting evidence that sugar, like alcohol and tobacco, is addictive. Oatman speaks to an economist who has crunched the numbers and believes that a penny-per-ounce soda tax (like the one proposed in Richmond, California) could actually be enough to persuade consumers to quit their Big Gulp habits. The revenue from such a tax could also be used to pay for health care and education.
But as Oatman also points out, the idea of a soda tax is nothing if not divisive. Which means it should make for a fun debate. We're lucky to have two experts to facilitate a conversation on the subject and answer reader questions: nutritionist and author Marion Nestle, whose new book is called Why Calories Count: From Science to Politics, and MoJo food and ag blogger Tom Philpott. Got a question for Nestle and Philpott? Leave it in the comments section, tweet it at @Econundrums, or email it to email@example.com. We'll be updating this post with more questions and answers as they come in.
To get things rolling, we asked Nestle and Philpott: Is soda really what's making us fat, anyway?
Marion Nestle: Excess calories are what make people fat. Consuming more calories than are expended in body functions and activity. The calories can come from anywhere, but the calories from sugar sweetened beverages differ in two ways from food calories: They have no nutrients accompanies their sugars (the calories are "empty"), and they are in liquid form. We are seeing increasing evidence that the body does not regulate liquid calories as well as it regulates calories that are absorbed more slowly from foods. That's why the Center for Science in the Public Interest calls sugary drinks "liquid candy," and why advice saying "don't drink your calories" makes such good sense.
Tom Philpott: I agree with Marion, with a possible caveat. First, there's strong circumstantial evidence that added sweeteners play a big role in the obesity problem. US obesity rates were pretty stable until about 1980, when they began to rise rapidly. The CDC tells us (PDF) they doubled between 1980 and 2000. Perhaps not coincidentally, per capita sweetener consumption began to rise dramatically over that same period—USDA figures tell us that we took in about 120 pounds of sweeteners per person per year in 1980, and by 1999 we were ingesting 151 pounds. That's a 25 percent jump.
Driving this surge was the rise of cheap high-fructose corn syrup, used heavily by the beverage industry beginning in the early 1980s, the consumption of which went from 19 pounds annually per capita in 1980 to more than 60 pounds by 1999. Since then, under pressure from health worries, sweetener consumption has come down; the latest figures, from 2010, indicate that we're taking in 131 pounds of total sweetener (of which 49 pounds are HFCS). Still, that's 8 percent more total sweeteners than we consumed in 1980 (which I remember as a pretty sugar-soaked time).
And USDA figures are averages—some people avoid added sweeteners, while others are still swilling sugary soft drinks like it's 1999. As for Marion's empty-calories analysis, The New York Times Magazine journalist Gary Taubes has marshaled considerable evidence that isolated sweeteners—conventional sugar and HFCS alike—are not just empty calories, but are downright toxic. According to Taubes and the science he cites, these substances are metabolized in a way that gives rise to excess fat and insulin resistance. I certainly don't have the scientific chops to evaluate Taubes, but his analysis is compelling.