Demands for biofortified food crops in three sub-Saharan African countries

Thesis (PhD)--University of Pretoria, 2019.This study determines consumer demand for staple food crops biofortified with micronutrients in three sub-Saharan African countries. Specifically, the study investigates how the choice of a valuation technique for a nonmarket good or new product, and gender, influence acceptance of biofortified food crops. Biofortification, a new public health intervention for alleviating micronutrient deficiency problems in developing countries, is achieved by enhancing the micronutrient content of staple food crops using conventional plant breeding or biotechnology. The rural poor in developing countries are likely to benefit most from biofortification, for two main reasons. Firstly, their diets are primarily comprised of staple foods that are usually poor sources of micronutrients. Secondly, they have limited access to fortified food products, mineral and vitamin supplements. The novel property of biofortification, however, has been associated with changes in the intrinsic properties of staple food crops that may not be familiar to consumers. Thus, knowing consumers’ attitudes and potential reactions to such changes in their staple food crops has been important to researchers and marketers alike. The study employs hedonic evaluations and incentive-compatible economic experimental data from HarvestPlus that aimed at determining consumer acceptance of micronutrient biofortified staple food crops in three sub-Saharan countries, i.e., Nigeria, Rwanda, and Zambia. The first objective compares the Becker–DeGroot–Marschak (BDM) mechanism to the non-hypothetical choice experiment (nHCE) in revealing the willingness to pay (WTP) for a new maize variety biofortified with vitamin A, under a field setting in Zambia. A mixed logit model was used to determine consumers’ WTP for the biofortified orange maize, relative to the two local maize varieties in the nHCE. While a symmetrically censored least square (SCLS) model was used to determine consumers’ WTP for the biofortified orange maize in the BDM experiment. The results show that the nHCE yielded significantly higher WTP estimates than that from the BDM mechanism. The second objective, related to the first, explored potential reasons for the WTP disparity between the BDM and the nHCE. The results indicate that accounting for additional training in the BDM experiment and lexicographic behaviour in the nHCE, together resulted in a decrease by half in the WTP estimates difference between the two methods. This difference, however, remains statistically significant. The third objective determined whether the gender of the decision-maker is important in determining consumer’s attitudes and behaviour towards biofortified food crops. Specifically, the study explores gender differences in hedonic preferences and consumer valuations of food products made from biofortified food crops. Emphasis was placed on the statistical analysis methods that incorporate gender while fully accounting for sources of both the observed and unobserved heterogeneity across gender. Results suggest that the gender of the decision-maker may be an important factor in both hedonic preferences and WTP for biofortified food crops, although the results varied across three countries. In Zambia and Rwanda, gender differences were observed in hedonic preferences for vitamin A-biofortified orange maize and biofortified iron beans respectively, while no evidence of gender differences was observed in hedonic preferences for vitamin A biofortified cassava in Nigeria. On the other hand, gender differences in WTP for biofortified foods were observed across the three countries in the respective biofortified food crops. While it is not yet clear how the BDM and the nHCE can result in significantly different empirical estimates under similar conditions, these results suggest the solution could lie in controlling for design effects from the two techniques. Similarly, controlling for gender differences not only in the outcome variable but also in its determinants may be necessary to attain valid estimates of consumer acceptance of biofortified foods.Agricultural Economics, Extension and Rural DevelopmentPhDUnrestricte