This article focuses on marketing of agricultural crops in Tanzania, with a particular emphasis on maize. The study concentrates on Arusha and Rukwa Regions, and data for production, prices, and transport costs are related to the year 1989/90, representing the situation before the deregulation of the marketing system came into effect. A linear programming model has been constructed, describing possible patterns of transport and storage for marketing the crops. Surplus and deficit production areas within and outside the regions have been defined, and quantities to be delivered to different markets have been estimated. The model is basically a supply model for the marketing system, considering purchase and sales prices as exogenous variables. Two model variants have been introduced: (1) A contribution margin model, which is a relevant reduced supply model under a market-oriented system. This model is maximising the contribution margin of the transporters. (2) A model for maximising marketed quantities, assuming that the total contribution margin of the transporters should be nonnegative. The latter model is relevant in the case of a single parastatal marketing agent, being supposed to subsidise among areas and crops. The article discusses the short and long-term effects of a gradual transition to a market-oriented system. The main conclusion is that, in a medium and long-term perspective, dramatic changes in the geographical pattern of production may take place unless regional and sector-oriented policies are introduced to counteract such a development.
Read
