copyright 2009 The Washington Post Like bears to honey or zombies to brains, politicians find something irresistible about soda taxes. President Obama recently told Men's Health magazine that he thinks a 'sin tax' on soda is 'an idea that we should be exploring.' San Francisco Mayor Gavin Newsom moved to impose a fee on stores for selling sugary drinks, only to admit that his plan was probably illegal. In December, New York Gov. David Paterson proposed a 18 percent tax on full-sugar soda to help cover a budget shortfall. After a public outcry, he claimed he was just raising awareness about childhood obesity. But he was also rehashing the same old myths about how taxing soda will save us all: 1 Sin taxes are for our own good. The basic idea sounds reasonable enough. Why not have the government nudge citizens along the path to righteousness by making bad choices more expensive? But even the most avid proponents of sin taxes concede that none of the nickel-and-dime proposals on the table is large enough to discourage soda drinking. And they're not really intended to. Soda taxes, like most sin taxes, aren't primarily designed to reduce consumption -- they're designed to raise revenue. Tap water is already virtually free. Adding a few cents in tax to a $1.29 soda bottle isn't going to send cost-conscious Coke-guzzlers swarming to the nearest water fountain. Forty states currently take a bite out of sales of soda or junk food -- if anyone's addicted to soda, it's state legislatures. In the Men's Health interview, Obama focused on childhood obesity. But the Senate Finance Committee's interest in soda taxes at a hearing this spring wasn't about keeping American spawn slim; health-care reformers were s! alivating over the projected $24 billion in revenue that a 3-cent tax would generate over the next four years. 2 Soda is causing the obesity epidemic. It's true that, on the whole, fat people drink more soda than skinny people. They also consume more calories overall and exercise less. So soda does help people pack on the pounds. But so does absolutely everything everyone eats. No news story about soda is complete without the scolding phrase 'empty calories,' yet soda consumption per capita has remained steady over the past two decades as obesity numbers have continued to rise. Weight gain is a function of calories in minus calories out. A food calorie is 4.2 kilojoules of energy, whether it comes from a bottle of orange juice, a latte or an ice-cold Coke. Cola calories are not uniquely 'empty.' They are not bleak, hollow shells of calories, staging tiny productions of 'Waiting for Godot' in your love handles. A calorie is a calorie. 3 Soda taxes help everyone. Even advocates of soda taxes admit that the costs will be borne disproportionately by the poor, who spend a larger percentage of their income on soda than other groups. Nonetheless, politicians continue the long tradition of taxing the wazoo out of a can of Coke while leaving upscale beverages and luxury foods sin-tax-free. Eight ounces of Naked's Mighty Mango juice ($3.79 a bottle at Whole Foods) contains slightly more sugar than the same serving of cola, while diet soft drinks have the same calorie count as water. But nationwide, fancy juices and venti mocha Frappuccinos remain almost completely untouched by sin surcharges, while a bodega bottle of Sprite brings down the wrath of the taxman. It's the silly, sugary equivalent of the distinction between the harsh sentencing guidelines for people caught with crack vs. the lenient sentencing for possessors of cocaine, its high-class cousin. 4 High-fructose corn syrup is extremely hazardous to your health. It's the stuff that makes soda sticky sweet -- and the reason many justify a soda tax. Florida state Rep. Juan Zapata called it the 'crack of sweeteners' and tried to ban it in schools in 2006. At the popular blog Slashfood, it's known as 'the devil's additive.' High-fructose corn syrup has been treated as the fall guy for America's obesity problem. But the hazards of cheap corn sweetener are the stuff of pseudo-scientific legend. New York University nutritionist Marion Nestle, a major proponent of soda taxes, has said of corn syrup: 'It's basically no different from table sugar. ... The body can't tell them apart.' Even the head of the self-proclaimed 'food police' has denounced high-fructose fear-mongering. Michael Jacobson of the Center for Science in the Public Interest tore into a 2004 scientific research report that kicked off anti-corn-syrup hysteria, saying, 'The authors of this paper misunderstood chemistry, draw erroneous conclusions and have done a disservice t! o the public in generating this controversy.' 5 Obesity is driving health-care costs up. A soda tax is just a user fee. Should we consider soda taxes an advance payment for all those diabetes tests and emergency room visits down the road -- not to mention the cost of buying the inevitably necessary super-size MRI machines? A group of academics, state health commissioners and others take exactly that line in the pages of the New England Journal of Medicine this month, writing, 'Escalating health care costs and the rising burden of diseases related to poor diet create an urgent need for solutions, thus justifying government's right to recoup costs.' But there is a dangerous precedent at the root of this argument: that government can and should tax any behavior that hurts the budget's bottom line. That logic sends us down a strange road. It's just a slouch, sink and a slump to taxing remote controls, thus encouraging the fat and lazy to get a little exercise by standing up to change the channel. All kinds of private decisions -- good and bad -- affect government spending. That doesn't give politicians the right to use taxes to push people around. -- Mangu-Ward is a senior editor at Reason magazine. 