To be effective, soda taxes must be high

ATLANTA — Small taxes on soda do little to reduce soft drink consumption or prevent childhood obesity, but larger levies probably would, according to new research.

The study is being released as a recent wave of proposals would raise soda taxes or create new ones on sugared beverages. But they'll have to be a lot steeper than current taxes, which are generally 4 percent or less, said Roland Sturm, lead author of the new research.

"Small taxes will not prevent obesity," said Sturm, a senior economist at the Rand Corp. in Santa Monica, Calif.

Sturm and his colleagues used information from a 2004 national survey of about 7,300 fifth-graders. The researchers looked at how the children's height and weight had changed over the previous two years and how often the kids said they drank soda and sports drinks.

They found the taxes made no real difference on overall soda consumption or on obesity for kids overall.

However, if the taxes were more like 18 cents on the dollar, Sturm calculated it would make a significant difference.

The research is being published online today in the journal Health Affairs.