As Radley Balko noted this morning, New York Mayor Michael Bloomberg is seeking federal permission to prevent residents of his city from using food stamps to buy soda or other sugar-sweetened beverages. The New York Times reports that "public health experts greeted Mr. Bloomberg's proposal cautiously":

George Hacker, senior policy adviser for the health promotion project of the Center for Science in the Public Interest, said a more equitable approach might be to use educational campaigns to dissuade food-stamp users from buying sugared drinks. "The world would be better, I think, if people limited their purchases of sugared beverages," Mr. Hacker said. "However, there are a great many ethical reasons to consider why one would not want to stigmatize people on food stamps."

This concern about stigmatizing poor people should not be confused with a concern about imposing disproportionate burdens on them in the name of public health, because CSPI does support a sin tax on soda, a levy that hits people of modest means especially hard. As with cigarette taxes, another regressive public health intervention, the quasi-progressive justification is that punishing poor people for their consumption choices ultimately improves their lives by changing their behavior: The more the tax hurts them, the more it helps them. But the same logic also applies to the food stamp restrictions that Bloomberg wants, which have basically the same impact, making unhealthy choices harder to afford for the people who need the nudge most.

More on soda taxes here. I profiled CSPI in a 2003 Reason article that opened by describing CSPI founder Michael Jacobson's distaste for "liquid candy."