Food safety failures in informal food markets remain widespread, driven by the unobservability of food contaminants, information asymmetries between producers and consumers, and the lack of incentive to supply safe foods. Whether market-based mechanisms can support food safety improvements, and under what conditions such markets can emerge, remains unclear. These issues are salient in cyanide-safe cassava product markets, leading to serious health risks for hundreds of millions who consume cassava foods as a staple. We implemented a randomized controlled trial combined with experimental auctions among 1,200 small-scale cassava processors and 792 consumers in Nigeria to estimate supply and demand conditions that can lead to a market for safe gari (a cassava flour). We specifically evaluated whether training, price incentives, and information can spur the supply and demand of cyanide-safe gari in the same market. At midline, training alone and training combined with price incentive reduced cyanide concentrations by 14.7 and 17.5 ppm respectively, increasing WHO compliance by 35 and 70 percentage points. At a six-month follow-up, both effects persisted with near-equal magnitude 15.4 and 15.5 ppm reductions, and compliance gains of 69 and 74 percentage points.. Consumers were willing to pay more than processors required as a premium to produce safe gari, by a margin large enough to suggest that a market for safe food exists given simple processor training and consumer information. Overall, results show informal food markets can internalize safety when the costs of producing safe foods are low, and training and information are provided.
