Plusvalore e sfruttamento dopo Sraffa. Lo stato del problema[Surplus Value and Exploitation After Sraffa: The State of the Problem]

This article deals with a theoretical point: the alleged consistency of the Marxian notion of exploitation with the Sraffian theory of prices. The problem is examined in a historico-critical perspective. The discussion is centred on the idea that in a circular model of production with vertically integrated sectors the use of the real wage rate as a numeraire provides a way of measuring surplus labour as a difference between the quantity of labour commanded by a real wage unit, at prices of production, and the quantity embodied in the amount of any commodity which would exchange at such prices with the wage unit. This procedure runs against two basic objections. First, by concentrating the attention on the possibility of substituting wage-goods for labour in the process of price determination, it implies a loss of the fundamental Marxian distinction between abstract labour, considered as a source of value, and labour-power, a commodity. Only the latter dimension remains relevant. Second, the sectoral rates of surplus value defined in such a way are "natural" rates, with a purely notional character.