Trusted sorghum: simulating interactions in the sorghum value chain in Kenya using games and agent-based modelling

Development programmes are increasingly supporting inclusive value chains (VC), in which resource-poor farmers are included in commercially viable VC opportunities. Strengthening social capital elements between VC actors is key to improve the farmers' livelihood. This article presents a novel impact evaluation method called the VC-Lab to assess the effectiveness of such development programmes, including long-term effects. The method is based on a Public Private Partnership (PPP) in the sorghum VC in Kenya. It consists of different components: (1) a VC analysis; (2) games to assess risk attitude and trust relationships between VC actors; and (3) an agent-based model (ABM) to assess the long-term impact. ABM parameter settings are based on the outcomes of the VC analysis and game results. The level of trust of participating farmers delivering to the participating trader is significantly higher than the level of trust of non-participating farmers in their trader. ABM simulations indicate that in the long run the PPP will lead to higher levels of trust and increased income, whereby training is the key intervention mechanisms. The VC-lab proves to be a valuable evaluation tool. Application of the VC-lab to other VCs, to other commodities and in other countries is needed to test wider applicability of the methodology.