Improving willingness-to-pay studies for traditional food products in developing countries: Evidence using repeated experiments

Willingness-to-pay (WTP) studies for traditional food products are plausibly affected by unobserved decisions and strategic collusion between the experimenter and respondents. Similarly, WTP estimates in developing countries using a one-time survey might be inconsistent, as the acceptance of new products likely varies with exposure to product attributes. We use repeated experimentation, where subjects are randomised twice on treatments, to reduce hypothetical bias and account for dynamic convergences of consumers' preferences. We rely on longitudinal variation in treatments, which allows subjects' characteristics and setting to have little influence on WTP estimates. These experimental designs evaluated consumers' preferences for cakes from high-quality cassava flour (HQCF) and wheat flour mixtures in Nigeria. When analysed separately and combined in panels, we find a time- consistent, insignificant difference in consumers' preferences and WTP for all cake categories. Nonetheless, we find evidence of texture and moistness as favourable attributes of HQCF cakes. Intensifying agronomic research and processing techniques that enhance favourable attributes such as the texture and moistness of HQCF could improve acceptance.