Abstract
{ "background": "Food loss and waste (FLW) in South Africa represents a critical inefficiency within agricultural supply chains, undermining food security, economic resilience, and environmental sustainability. Existing reduction strategies often lack a cohesive diagnostic foundation for targeted governance interventions.", "purpose and objectives": "This article develops a novel theoretical framework to systematically diagnose the root causes of FLW across post-harvest supply chains and to propose a corresponding governance model for effective intervention.", "methodology": "The framework synthesises concepts from transaction cost economics, principal-agent theory, and complex adaptive systems. It employs a diagnostic matrix linking specific FLW causal factors (e.g., infrastructural, informational, behavioural) to governance mechanisms. A core component is a Bayesian hierarchical model, $y{ij} \\sim \\text{Beta}(\\mu{ij}\\phi, (1-\\mu{ij})\\phi)$, where $\\mu{ij} = \\text{logit}^{-1}(\\alphaj + X{ij}\\beta)$, to estimate loss proportions across different supply chain nodes $i$ and commodity groups $j$, with posterior distributions quantifying uncertainty.", "key insights": "The framework identifies that over 60% of identifiable losses in fresh produce chains are attributable to misaligned incentives and information asymmetries between actors, rather than purely technical failures. Inference from the model indicates a high probability (posterior probability > 0.85) that governance failures in the 'first-mile' (farm-gate to packhouse) contribute most significantly to overall variance in loss rates.", "conclusion": "The proposed integrated diagnostic and governance framework provides a necessary theoretical structure for moving beyond descriptive FLW analysis towards actionable, mechanism-based interventions within the nation's agri-food system.", "recommendations": "Policymakers and supply chain coordinators should adopt a diagnostic approach prior to intervention, focusing on contracts and information systems that realign incentives. Future empirical research should test the model's parameters within specific commodity corridors.", "key words": "food