Individual Working Time, duration of labour input by individual producers (enterprises) to manufacture a unit of output. This depends on the technical equipment and organisation of production, the workers’ skill, the intensity of their labour, and other factors that determine labour productivity. Thus individual working time may be more or less than the socially necessary work time. Under commodity production based on private ownership of the means of production, the contradiction between individual and socially necessary working time is antagonistic, leading to the differentiation of 159 commodity producers. Those who expend more working time than the socially necessary time on the manufacture of a unit of output incur losses and gradually go bankrupt. Others, whose individual expenditures are lower than the socially necessary ones, become richer. Among the latter are the big industrialists who use improved techniques and progressive methods of production organisation at their enterprises. This serves as the basis for the systematic ruin and ousting of small and medium-sized enterprises by the large ones. In socialist society, the contradiction between time expenditures on the manufacture of particular commodities at individual enterprises and the socially necessary working time is not antagonistic. It is resolved by society through the planned introduction of new technology and the planned improvement of production, better production organisation, and the systematic upgrading of workers’ skills. This results in lagging enterprises catching up with the advanced ones, and in the gradual elimination of the gap between individual and socially necessary expenditures of labour.