“By speeding up the supplanting of workers by machinery and by creating wealth at one extreme and poverty at the other, the accumulation of capital also gives rise to what is called the “reserve army of labor”, to the “relative surplus” of workers, or “capitalist overpopulation”, which assumes the most diverse forms and enables capital to expand production extremely rapidly. In conjunction with credit facilities and the accumulation of capital in the form of means of production, this incidentally is the key to an understanding of the crises of overproduction which occur periodically in capitalist countries….”
Vladimir Lenin, “Karl Marx”