Demand for agricultural commodities, particularly for basic food-stuffs, depends on a household's income, competitive prices, and a set of unique household characteristics which include tastes, location, education, family composition, and farm status. This monograph reviews disaggregated evidence at the national level on the relative contribution of each of these factors and performs statistical analysis of national aggregate data in a search for reliable patterns in this contribution. The paper examines patterns of food consumption of the poor and confirms that the poor are significantly more responsive to economic signals than higher income households. The food consumption parameters of low-income groups can thus serve as the basis for designing targeted food interventions that improve nutritional status without distorting the rest of the economy--an important objective for food policy decisions and implementation. (Author)