“…However, these two forms complemented each other, and only when the world system required the more advanced forms of production (agricultural or industrial) were they introduced. (See also Humphrey 1980;Pinto 1965;Sotelo Valencia 2014, p. 543) It is in this context that the contribution of Ruy Mauro Marini (2005a, b) to the labour theory of value, in the form of his thesis on superexploitation, is significant, insofar as it offers one of the most rigorous treatments of this apparent 'backwardness' to date (see also Bueno and Seabra 2010;Osorio in Almeida Filho 2013;Sotelo Valencia 2014; on the significance of this thesis to historical and contemporary debates within Marxist dependency theory, see Kay 1989;Prado 2011;Sotelo Valencia 2014). While many use the term figuratively or descriptively to talk about a variety of low-wage, physically exhausting and often dangerous work, Marini examined the historical function of superexploited Brazilian labour, unfree and free, in the production of particular use values for consumption in the metropolitan core during the nineteenth century.…”