In this paper the exploration of the interaction mechanisms between the evolution of demand and the overall process of differentiation of the economic system is pursued in a twofold way: (i) the question is asked whether demand indeed saturates and whether such saturation is required for an ongoing economic development; (ii) the impact of the income distribution on the evolution of demand and thus on economic development is investigated. To study the existence and impact of demand saturation, Engel curves are calculated under different conditions. To study the impact of income distribution, TEVECON distinguishes within the population of the economic system two social classes, which differ in their level and quality of education, and thus for their human capital and wages.