MARXIAN POLITICAL ECONOMY 61 value, the nature of capital as a social relation will become explicit. A V BALU * Capital, vol. I, Moscow, 1967, p 15k a Ibid. 8 /W,plb0 4 Ibid., p Ibk 8 Ibid . p 165. 6 Ibid. 7 It needs to be clearly understood that the assumption that commodities exchange at their values is made not because this is the casefeven approximately) in the market of the 'real world* everyday, hut because value is considered the basic determinant of the exchange-values of commodities, and because of the other arguments given in the beginning of this section. The forces of 'supply and demand^ so dear to bourgeois economics, do play an important role in the determination of actual exchange ratios, that is, prices, but one that is secondary and itself determined by the value-relations between commodities ^ he role of supply and demand v\il) Ie clarified subsequently See especially Capital vol I, p 166, footnote and vol III, pp 177-200. 8 Capital, vol. I, p 171. » Ibid. * ° In the USA, for instance, the Bureau of Labour Statistics publishes the annual incomes needed for a ^moderate* level of living for a family of four, as also poverty line income levels. »> Capital, vol I, p 170. *a JW.,pl68. »» /^W.,pj69. *4 Ibid. '» Ibid., p 167.