10. Further discussion, both analytical and descriptive, is necessary to clarify the meaning and the role of exploitation in capitalism. I have provided a fuller (though still brief) discussion in Chapter 2 of my U.S. Capitalist Development, noted earlier. Here it may be added that the existence, the pervasiveness, and the essentiality of exploitation require time and space to explain; but what determines the wages of labor in conventional economic theory – its “marginal revenue product” – cannot be established at all: it is unmeasurable, nothing more than a convenient analytical and ideological fiction.
In the contemporary world, it is notable that the degree of exploitation of the workforce in the leading industrial capitalist countries has been much reduced (as measured, for example, by the simultaneous increase of real income along with lessened working hours); but that has been made possible by the enormous increase in the numbers of exploited in the periphery.

To get a sense of the severity of exploitation in the United States at the turn of the century, see the novel of Upton Sinclair, The Jungle, which describes in Dickensian detail the horrors of life (and the poisoned product) of the meatpacking industry in Chicago. For England, earlier, see Dickens. Those conditions are the daily fate of many hundreds of millions more today, in Latin America, in Asia, in Africa – nor are these horrors totally absent in the United States.