[NOTE: Since the original publication of this blog entry, the classification “libertarian paternalism” has been corrected to “liberal paternalism.”]

I recently had a conversation with my good friend Justin who lamented that he had received his third parking ticket this year from the city of Madison, Wisconsin for violating the alternate side parking rule. “Alternate side parking is a racket designed to part the citizens of Madison with their hard-earned cash,” he told me.

I think that Justin is onto something, and this raises an additional concern that I have about aggressive ticketing and selective taxes: liberal paternalistic policies frequently fail to accomplish their official purpose.

The parking tickets haven’t changed Justin’s behavior; he continues to park on the side of the road that is arbitrarily wrong. The city’s alternative-side parking rules are so confusing and difficult to appeal, even smart people like Justin get trapped. Of course, that’s OK with the city; they’ll receive a steady revenue stream from parking tickets.

Selective taxes on fatty food and soda are another example of liberal paternalism that doesn’t accomplish their official purpose, which is to trim waistlines in aggregate. In this example, there is not a scientific consensus on whether they will accomplish that which they allegedly intend. In a recent piece on the Huffington Post, Dr. Pamela Peeke explains how many studies that prove the contrary are being ignored.

Last September, the New England Journal of Medicine published a policy report by a group of distinguished experts that called for taxing sodas and other sugary drinks to fight obesity. The news media gave a lot of attention to the report. But last month, the press did not give much attention to a group of letters from prominent doctors published in NEJM noting that the report failed to cite any scientific evidence showing a tax would reduce the cumulative weight of Americans.

Furthermore, slapping selective taxes on soda will be inefficacious at reducing obesity because an individual’s risk of obesity is not a direct function of the amount of sugary beverages that she consumes. Dr. Peeke argues that it is the result of many factors instead — some relating to genetics, others to lifestyle choices.

Government actually has an incentive for these taxes to be inefficacious, because then it can continue to generate revenue from them. I consider this to be further evidence that the primary purpose of new taxes to raise more tax revenue to support the government’s spending habit. Just like the indoor tanning tax, selective taxes on sodas and fatty food would be a revenue generator first and a behavior deterrent second. These taxes would easily generate a considerable amount of income for state and local governments. In a previous post on Show Me Daily, I used a revenue calculator for soft drink taxes from the Rudd Center for Food Policy and Obesity at Yale University to determine that Missouri could generate $285 million in 2010 if it taxed sugar-sweetened beverages at $0.01 per ounce, or over $460 million if this tax were expanded to include diet-beverages.

[Cross-posted at Amateur Philosophy]