Food Security, Fertility Differentials and Land Degradation in Sub-Saharan Africa: A Dynamic Framework

We study the impact of differential fertility levels for the food-insecure and foodsecurepopulation on the long-run values of the population distribution and resourcesin a descriptive model, where the food security states are determined by a historicallygiven food distribution and by the endogenous food production with resources andlabor as inputs. Furthermore, we assume that the resource stock is reduced by povertydrivenenvironmental degradation. Moreover, we incorporate nutritional effects on laborproductivity and mortality. By applying local bifurcation theory, we show that themodel may exhibit multiple equilibria. Furthermore, the orbits of resources and thepopulation distribution may be characterized by quasi-periodic behavior. Sustainabledevelopment in terms of approaching a steady state with positive values of resourcesand food-secure population is only promoted by low fertility levels of the food-insecureand food-secure population