Using a fractional model to measure the impact of antioxidant information, price, and liking on purchase intent for specialty potatoes

A procedure for analyzing categorical purchase intent data from consumer tests is demonstrated using data from a test of fresh market specialty potato varieties. Due to the probabilistic nature of purchase intent a fractional model is based, just as a binary choice analysis using probit or logit would be, on a non-linear cumulative distribution function. The results from a fractional model are compared to an ordinal model. Participants in the consumer test evaluated six unreleased varieties and one commonly available variety of potato, the Yukon Gold. Four of the new varieties had colored red or purple flesh rated highly for antioxidant content. The effect of antioxidant information and other variables on the probability of purchase for red and purple potatoes was compared to the effect on the yellow potatoes using a fractional model and an ordinal model. Other variables include liking, price, gender, age, education, income, potato usage frequency, health interest, and food interest. As expected hedonic ratings and price had significant positive and negative effects respectively on purchase intent for both categories of potatoes. Antioxidant information, whether simple or detailed, increased purchase intent for the colorful potato varieties. Interactive variables between health interest and antioxidant information level demonstrate the impact of personal health interest in conjunction with the information.