• Labor, being itself a commodity, is measured as such by the labor time needed to produce the labor-commodity. And what is needed to produce this labor-commodity? Just enough labor time to produce the objects indispensable to the constant maintenance of labor, that is, to keep the worker alive and in a condition to propagate his race. The natural price of labor is no other than the wage minimum.

    Karl Marx, Friedrich Engels (2016). “Delphi Collected Works of Karl Marx (Illustrated)”, p.326, Delphi Classics