PhD Thesis
Consumers’ preferences for food products are always based on observable and non-
observable attributes. Common beans which are globally important for income generation
as well as food and nutrition security, appeal to consumers in different ways. One
important distinction of this nature is with respect to colour, size, cooking time and gravy
quality. When multiple common beans’ varieties with varying attribute levels are exposed,
consumers normally select multiple varieties on the same occasion while rejecting some of
the offerings. However, studies that have explicitly assessed factors underlying such a
decision making have generally been rare and confined to demographic and socio-
economic factors only. Factors such as societal and cultural have been ignored in the
previous studies. Ignoring these factors can distort the measured effects and contribute to
the failure of interventions aimed at altering food preferences. This study incorporated the
factors ignored in the previous studies along with demographic and socio-economic
factors to understand better consumers’ preferences for the common bean in Dar es
Salaam, Tanzania. The rationale was to identify means to support actors in the bean value
chain to improve their businesses and wellbeing. Discrete Choice Experiment (DCE) was
employed in order to elicit individual preference and uncover how individuals selected
common beans with varying attributes levels using a random sample of 732 respondents.
Four different attributes including colour (4 levels), grain size (3 levels), cooking time (2
levels) and gravy quality (2 levels) were studied. Data analysis involved the use of
descriptive statistics and Poisson Regression Model (PRM). Results from descriptive
statistics showed that common beans with yellow colour, small grain size, good gravy and
shorter cooking time were the most preferred. However, common bean with mottled red
colour, poor gravy and longer cooking time were the least preferred. Results from PRM3
showed that the probability of choosing two common beans types was the highest,
although for some consumers, the number of choices ranged from zero to eight. The
observed wide range of consumers’ choice of beans reflect the diversity of consumer
preferences which are partly influenced by their food habits and other factors including
demographic, cultural orientation and economic factors like levels of income and
occupation. The study recommends that breeding and market development efforts should
primarily focus on both most preferred type of common beans and unique preferences of
consumers whose choices are predominantly within a narrow range of common beans.
Meeting the varied demand of consumers means increasing the range of choices that
appeal to consumers.
SFSE - University of Pretoria