Will subsidizing healthy food lead to buying more junk?

No one said changing the world would be easy.

Certainly one of the strategies put forth to change our nutritional environment is the subsidization of healthy foods.

The theory is pretty straight forward - make healthier foods cheaper and people will buy more of them.

The practice may be slightly different than the theory.

A paper published ahead of print in the journal Psychological Science studied the effects of healthy food subsidizies on the purchasing behaviour of 42 mothers. Half were from low-income families and half high. All moms had at least one child between the ages of 6 and 18 at home and all moms were their family's primary grocery shopper.

Researchers set up a make believe grocery store and divided food into high-calorie for nutrient foods (bad foods) and low-calorie for nutrient foods (good foods) based off of Drewnowski's scoring system.

Participants were given $22.50 in make believe dollars and told to imagine that she had no food in the house and she was to purchase groceries for her family for the week. Prices of foods were based off grocery prices and different scenarios were played out.

Two of the scenarios involved lowering the prices of the good for you foods.

The results?

When good for you foods were subsidized moms did in fact buy more of them. But they also bought more bad for you food - in fact they bought more extra bad for you food than extra good for you food. When the price of the good for you foods was lowered by 10%, moms bought 10.3% more bad for you food but only 6.8% more good for you food.

The authors' conclusions?

If we're looking to use pricing to motivate healthier dietary choices sticks (taxes) may well work better than carrots (subsidies).

Epstein, L., Dearing, K., Roba, L., & Finkelstein, E. (2010). The Influence of Taxes and Subsidies on Energy Purchased in an Experimental Purchasing Study Psychological Science, 21 (3), 406-414 DOI: 10.1177/0956797610361446