Food Demand, Food Sensory Preferences and Attributes Explaining Food Price Differences

Abstract

This dissertation evaluates staple food demand in Burkina Faso, specialty coffee sensory attributes and their relation with coffee quality and the effect of material and reputation attributes on specialty coffee quality scores and purchase prices. Chapter One focuses on determining economic and non-economic factors affecting demand for staple cereal commodities in Burkina Faso using the Almost Ideal Demand System (AIDS) model. Results show that millet, maize, sorghum and rice are the main staple cereals. However, we found that millet, maize, and sorghum are necessities while rice is a superior cereal. Disaggregated analyses reveal that households’ consumption patterns change depending on their location, income and education level. The analysis of the evolution of cereal prices shows an overall increase over the period 1996-2009, leaving many people in food insecurity and the country in political instability. Therefore, the government needs to adopt policies that help lower food prices to avoid future food riots. In Chapter Two, we relate specialty coffee cuppers (tasters) and buyers preferences to sensory attributes using descriptive analyses. Principle component analysis (PCA) shows that specialty coffees can be clustered into five groups based on their flavor profiles. The analysis of variance (ANOVA) reveals a significant difference among the means of the five groups. The Tukey-Kramer (TK) method, used for pairwise comparison of the means for the five groups, shows that coffees with sweet, berry and sour flavor profiles have higher mean quality scores and purchase prices, while coffees with brown sugar, other fruit and brown spice flavor profiles have lower mean quality scores and purchase prices. Also, the results reveal that complexity and uniqueness are rewarded with high quality scores and high purchase prices. Since Chapter Two show specialty coffee cuppers and buyers preferences for sensory attributes, the next task is to evaluate the value cuppers and buyers put on those attributes. Therefore, Chapter Three uses the hedonic price technique to measure the value that specialty coffee cuppers and buyers place on material, physical and reputation attributes. The estimation of the quality score equation suggests that material and physical attributes are important determinants of quality. However, reputation attributes have greater explanatory power on quality scores. This result is surprising because the coffee quality score is determined in a blind evaluation, which is independent of reputation attributes. Results of the estimation of the hedonic price show that specialty coffee price is essentially determine by reputation attributes and market conditions such as the number of coffees in the auction. Overall, the analyses show that demand for food depend on economic and demographic variables, sensory attributes affect food quality and price, and reputation attributes explain more of food quality score and price differences than material or physical attributes.