How to incentivize peanut producers to adopt post-harvest aflatoxin control measures: A field experiment in Haiti

Aflatoxin contamination in peanuts represents a significant public health concern in many developing countries, including Haiti, a low-income country. Although simple post-harvest mitigation measures exist, their adoption by Haitian farmers remains limited. This study assesses the willingness to accept (WTA) of peanut producers in Haiti to implement post-harvest measures, using a reversed Becker-DeGroot-Marschak (BDM) auction. It also tests the effect on WTA of a conditional market access. For one group the research project commits to purchase peanuts at a predetermined price if aflatoxin levels meet a maximum of 10 parts per billion, while another group receives unconditional market access at the same predetermined price. Moreover, Haitian supermarket consumers’ willingness to pay (WTP) a premium for a local peanut butter (mamba) certified to meet aflatoxin standards is explored. Results indicate that conditional market access generates higher WTA. Haitian supermarket consumers show strong interest in certified peanut butter, with a declared premium of 21.1 % over the market price of a 16-ounce jar of non-certified peanut butter. If we consider intermediary margins as high as 86 % of the final consumer price—well above the current 68 % reported in previous studies—as well as for a potential hypothetical bias as high as two thirds of the stated WTP, this premium is sufficient to incentivize Haitian peanut producers, measured by their observed WTA. Thus, a market solution to the aflatoxin problem in Haiti seems plausible for supermarket consumers.