Show and tell: farmer field days and learning about inputs with heterogeneous yield effects.

This article examines the effectiveness of farmer field days (FFDs) in disseminating information about novel organic agricultural inputs—specifically biochar and vermicompost—and their impact on smallholder farmers' willingness to pay (WTP) for these inputs in western Kenya. Using experimental auctions and an instrumental variable approach based on the distance between farmers' homesteads and FFD locations, the study finds that exposure to information from FFDs significantly decreases farmers' WTP for these organic inputs by about 28–33 percent. The authors suggest this decline is likely due to updated perceptions of lower expected profitability and the high variability of yield outcomes demonstrated at FFD sites, which generate uncertain and heterogeneous information signals. The study highlights both the potential and limitations of FFDs as cost-effective tools for agricultural technology diffusion in developing country contexts, emphasizing the need for careful consideration of how information variability influences farmer demand.