TRANSITIONS BETWEEN CULTIVATION AND PASTORALISM IN SUB-SAHARAN AFRICA

This paper presents a dynamic optimality model of herding and farming as long-term survival strategies. The model can be used to predict which modes of subsistence will be associated with different ecological and economic conditions and therefore to examine under what circumstances people might change from one mode of subsistence to another. It predicts that the shift into pastoralism is associated, principally, with increasing wealth, and examples from recent history support this. It also explains such counter-intuitive behaviour as pastoralists' taking up cultivation in an area although farmers are moving out.