What kinds of incentives drive consumer behavior most? Is it punitive measures for an undesired response, or reward for doing something good?

A new study, set to launch in January, by University of Cornell researchers at the College of Agriculture and Life Sciences and the College of Human Ecology seeks to answer those questions when it comes to food and how healthy — or unhealthy — Americans eat.

Would a tax on unhealthy foods help curb high obesity rates in this country? Or, would a rebate on the purchase of healthy items prompt consumer behavior in more nutritious directions?

It’s the dietary version of the carrot or the stick question.

Brian Wansink, professor of marketing and director of Cornell’s food and brands lab, and the lead researcher on the study, has a good idea on what the study will show.

“There are a lot of people who believe there should be taxes on unhealthy foods,” said Wansink, who has also authored a book, “Marketing Nutrition.” “That comes from a viewpoint of not necessarily taking into account how consumers think.

“If you look into years of agricultural research, people tend to be pretty price insensitive when it comes to foods they really like.”

That’s the stick, Wansink said.

“The alternative is the carrot,” he said. “If people think they’re going to get some rebate, maybe get twice as much for your money, it might be an entirely different animal. It might be that little nudge we need versus something that might be a little more indulgent.”

The researchers plan to recruit 200 families for the six-month study at three Hannaford’s supermarkets in Utica, N.Y. The families will be divided into four groups — one which will be taxed for unhealthy foods, one which will receive rebates for choosing healthy products, one both taxed and receiving rebates and a control group.

Hannaford’s was selected because of its Guiding Stars program which rates food on its shelves through a star system, with zero stars being least healthy and three stars for most nutritious. The study also will evaluate how consumers react to that system.

The study is being supported by a nearly $1 million grant from the National Institutes of Health via the stimulus funds in the American Recovery and Reinvestment Act.

“People can do some pretty fakey lab studies, but nothing beats going into the field and see what happens,” Wansink said. “I think it’s the only way this is going to be settled, instead of what people yell loudest.”

Study seeks answers about healthy consumer purchases