NEW YORK - An article in the Washington Post earlier this week focused on New York City??s rejected proposal to ban the use of food stamps to purchase soda.

The USDA rejected the proposal last week, explaining that the move would have required a waiver from the Agriculture Department, and as such, "[T]he waiver the city sought was denied because of the logistical difficulty of sorting out which beverages could or could not be purchased with food stamps??"

The article moved past the news item and focused on whether the proposal would have actually worked. That is, "Does banning the use of food stamps to purchase soft drinks actually reduce consumption of soft drinks, thereby lowering obesity rates?"

The answer, according to recent food policy research, suggests that it would not have made much of an impact.

A 2007 USDA report revealed that financial barriers to soda do lower consumption, but not significantly.

"[A] 10-percent reduction in milk price would result in a 14-percent increase in the consumption of reduced-fat milk, and a 10-percent increase in soft drink price would lead to an 8-percent reduction in soft drink consumption." The report concluded that "price manipulation may have varying effects on food purchases across different foods." That is, consumption for fruits and vegetables would be more profoundly affected than it would for soda and junk food.

Also, if food stamps couldn??t be used to purchase soda, consumption would fall in lower income areas and the prices would subsequently decrease, thereby stimulating higher soda consumption ?" the opposite effect as desired.

The authors of the USDA report concluded that changes to what food stamps cover would "likely be an ineffective and inefficient instrument for bringing about desired nutritional outcomes."

The Washington Post noted that the article??s research is theoretical, and that no states have yet to test what would actually happen in practice.