Sustainability of impact: dimensions of decline and persistence in adopting a biofortified crop in Uganda
3ie Impact Evaluation Report 35
This study by McNiven, S, Gilligan, DO and Hotz, C, studied the sustainability of impact of an agricultural intervention that promoted the adoption and consumption of biofortified orange sweet potato by farming households over two periods -- during the project and over four seasons after the project ended. Researchers found that the high adoption rate in the first season declined steadily and even accelerated after the project ended. There was substantial heterogenity in the adoption pattern among initial adopters that was followed by a period of learning about profitability and consumption preference for the crop. The authors also explore the mechanisms that predict decline and persistence in adoption behaviour among various types of farmers and consider implications for the cost-effectiveness of the intervention.