Elementos de teoria de demanda de mercado

This paper explores implications on the market demand stemming from the inequality of income distribution, based on the more usual assumptions made by microeconomics with respect to consumers, as independent deciders who present well-behaved utillty functions. The analysis presents no assumption about income distribution, its continuity, or its shape; nor is it restrieted to specific forms of demand functions, but rather deals with aggregation on consumers in more general conditions. The market demand founded on the equilibrium of a set of consumer units with differing incomes focuses on the need of defining an inequality effect (difference between the average demand for a good and the respeetive demand of the typical consumer unit, the one who receives the average income) and the existence of limit functions of income-consumption to be used when there is inadequate information to determine the collective incomeconsumption function. The study presents an expansion of the Slutsky equation to include the price effect on the market demand for a good. The expanded Slutsky equation represents the adjusting movement of the typical consumer unit in terms of the demand for a good in the face of the change in one of the prices, to which are added the effects of this change on the inequallty effect. These added effects are a pure substitution effeet, all consumer units (including the typical) being held at their respective satisfaction levels, and an income effect on the inequality effect. The study shows that aggregated demand functions ean be treated, with respect to the price effect, in a way similar to the analytical treatment usually applied to individual demand functions.