Agri-food supply chains and sustainability of households’ livelihood outcomes among sunflower smallholder farmers in Tanzania

Agri-food supply chains play a substantial role in shaping the household livelihoods of smallholder farmers. However, the sunflower supply chain has been reported to exhibit structural and operational deficiencies that limit its contribution to sustainable livelihood outcomes. Guided by the Sustainable Livelihood Approach, the study assessed the impact of supply chain activities on household livelihood outcome sustainability in Iramba District. A quasi-experimental design was employed where cross-sectional data was collected from five villages. Propensity Score Matching and Difference in Difference techniques were used to address selection bias and estimate the causal effects. Findings show statistically significant differences in the status of livelihood outcome sustainability potentials between treated and control households, particularly in cash savings (t = 3.62; p = 0.000; MD = 220845.07), land ownership (t = 0.96; p = 0.033; MD = 1.5258), and household assets (t = 3.21; p = 0.000; MD = 1.5258). The differences are attributed to households' participation in the sunflower supply chain activities based on a counterfactual analysis of the observable characteristics. Therefore, participation in the sunflower supply chain activities significantly influences the livelihood outcomes and sustainability potential among households, though not spontaneously. The study recommends diversification of livelihood activities along the supply chain to enhance households’ income and sustenance level, particularly for households with lower livelihood outcomes and sustainability potentials.