For Marx, the fundamental crisis tendency of the capitalist mode of production was not limited in its scope to periodic downturns in economic activity. It revealed itself most forcefully in a permanent crisis of working life. The differentia specifica of capitalist “economic” crises — that people starve in spite of good harvests, and means of production lie idle in spite of a need for their products — is merely one moment of this larger crisis — the constant reproduction of a scarcity of jobs in the midst of an abundance of goods. It is the dynamic of this crisis — the crisis of the reproduction of the capital-labour relation — which this article explores. Endnotes, Misery and Debt, On the Logic and History of Surplus Population and Surplus Capital, Endnotes #2 (2010), https://endnotes.org.uk/articles/misery-and-debt

This is the secret of the “general law”: labour-saving technologies tend to generalise, both within and across lines, leading to a relative decline in the demand for labour. Moreover, these innovations are irreversible: they do not disappear if and when profitability is restored (indeed, as we shall see, the restoration of profitability is often conditioned on further innovations in new or expanding lines). Thus left unchecked this relative decline in labour demand threatens to outstrip capital accumulation, becoming absolute. […] What Marx is here describing is not a “crisis” in the sense usually indicated by Marxist theory, i.e. a periodic crisis of production, consumption or even accumulation. In and through these cyclical crises, a secular crisis emerges, a crisis of the reproduction of the capital-labour relation itself. If expanded reproduction indicates that workers and capital pushed out of contracting industries will try to find places in new or expanding lines, the general law of capital accumulation suggests that, over time, more and more workers and capital will find that they are unable to reinsert themselves into the reproduction process. In this way the proletariat tendentially becomes an externality to the process of its own reproduction, a class of workers who are “free” not only of means of reproduction, but also of work itself. For Marx this crisis expresses the fundamental contradiction of the capitalist mode of production. On the one hand, people in capitalist social relations are reduced to workers. On the other hand, they cannot be workers since, by working, they undermine the conditions of possibility of their own existence. Wage-labour is inseparable from the accumulation of capital, from the accretion of labour-saving innovations, which, over time, reduce the demand for labour: “The working population ... produces both the accumulation of capital and the means by which it is itself made relatively superfluous; and it does this to an extent which is always increasing” [Marx, Capital, vol.1 (MECW 35), p. 638]. It might seem that the abundance of goods, which results from labour-saving innovations, must lead to an abundance of jobs. But in a society based on wage-labour, the reduction of socially-necessary labour-time — which makes goods so abundant — can only express itself in a scarcity of jobs, in a multiplication of forms of precarious employment. Endnotes, Misery and Debt, On the Logic and History of Surplus Population and Surplus Capital, Endnotes #2 (2010), https://endnotes.org.uk/articles/misery-and-debt