A longstanding misunderstanding is that smallholder agriculture — African agriculture is overwhelmingly carried out on small family farms — is marked by stagnation in yields per hectare and returns to labour, if not outright involution, as increasing numbers of farmers try to support themselves on ever-smaller patches of overworked soil so that productivity actually falls. This simply isn’t true. Not for agriculture: it is two decades since Martin & Mitra found that total factor productivity in most countries across the world grew faster in agriculture than in other sectors. Taking the partial measure of labour productivity —arguably the most important measure since it so closely relates to incomes and wages — productivity of farm labour has typically been faster in agriculture than in other sectors over the last half-century.
We know too little about what drives such increases, where they take place, for which crops, in which regions, and for which farmers. If our understanding of change on the farm is sketchy, then all the more so for changes in supply chains. What do we know of labour productivity in trading, processing, transport and storage? Next to nothing, other than case studies and anecdotal accounts that suggest some very large changes in the few chains where there has been some observation.