Piero Sraffa - Free

130 Piero Sraffaas it may be) and on those variables directly relevant to the problemin question, without denying the existence of other problems to beaddressed with other ‘language games’ and, in particular, without denyingthe indirect influence of other variables.Hence, it is clear how misguided any attempt might be to extrapolatemechanically Sraffa’s theoretical position in other fields from the analysisillustrated in Production of Commodities by Means of Commodities. Inother words, we cannot expect to extend Sraffa’s analysis by associatingwith his equations other equations, expressing other aspects of theeconomy, as if the new equations belonged to the same analytic areaor were part of the same language game. Nevertheless this is preciselyhow neoclassical interpreters act when they set out to complete thehalf system of general economic equilibrium Sraffa is supposed to haveanalysed, adding to his ‘supply’ equations, which refer to given levelsof production, a set of demand equations, representing quantitiesdemanded as functions of prices.A point worth stressing here is that this difference in method holdsimportant implications for the significance to be attached to theconcepts Sraffa analyses, generating appreciable differences from thecorresponding concepts as approached within marginalist analysis. Inparticular, within the marginalist approach the concept of equilibriumrefers to a state of equality between demand and supply (market clearing)throughout the economy. Within the classical approach, on the otherhand, as far as the concept is applicable, 26 reference is simply to theabsence of incentives to transfer capital from one sector of the economyto another (‘competitive equilibrium’). Thus it is evidently a mistaketo confuse Sraffa’s prices of production (and the natural prices of theclassics) with the ‘normal prices’ or ‘long period equilibrium prices’ ofmarginalist analysis.26As we have seen, the concept of equilibrium adopted in all the variousstreams of the marginalist tradition derives from physics, more precisely fromclassical mechanics, with reference to conditions of equilibrium implying staticanalysis. By contrast, reference to the dichotomy between static and dynamicanalysis appears inappropriate in terms of the classical approach; cf. Roncaglia(1975: 119).Some post-Keynesian economists (cf. for instance Kaldor 1972) argue thatthe concept of equilibrium is to be rejected in toto, given the frequent occurrenceof increasing returns in the economy: there are good reasons for thisidea, if reference is to the notion of equilibrium imported from classical mechanicsinto marginalist theory; but there is some exaggeration, if rejection also involvesthe competitive hypothesis of a uniform rate of profits in the various sectors ofthe economy, as employed by the classical economists and Sraffa.Interpreting Production of Commodities 131At this point we are faced with a problem which we shall verybriefly outline here. If we accept the idea of a separation betweenthe various ‘language games’, and in particular between analyses ofdifferent problems – for example, if we distinguish the analysis of thelink between prices and distribution from the analysis of the factorsdetermining the levels of production or technology, or the distributionof income itself – there will no longer be any need to construct a singlegeneral model in which to include the various ‘pieces of analysis’ as fittingparts of a whole. Instead, each piece of analysis implies a distinctprocess of abstraction, belonging to its own ‘analytic area’, and noclassification of decreasing generality can be determined between thevarious areas. 27A problem remains, concerning the internal consistency of the conceptualframework – or conception of the way the economic systemfunctions – within which the various pieces of analysis addressingthe different problems are to be inserted. For example, a monetaryexplanation of the rate of profits as referred to by Sraffa (and whichwe shall be returning to shortly) is not compatible with a marginalisttheory of value, where the distributive variables are the prices of theservices of productive factors. An issue we shall consider in this light –as a problem of consistency of their conceptual frameworks – is thecomplex question of the relationship between Sraffa’s and Keynes’sanalyses. 287.6 Sraffa and KeynesAs we have seen, Sraffa’s analysis may be located as falling withina classical conception, where the task assigned to economic theoryis to establish the conditions for reproduction of the system and toanalyse its evolution over time. The various problems are obviously27For example, it would indeed be difficult to attempt such a comparisonbetween Sraffa’s analysis of prices and Harrod’s analysis of the warranted growthrate. The term ‘analytic area’ was suggested by Ian Steedman since it does notimply the possibility of ordering in a sequence of decreasing abstraction the differentanalytic areas. This latter idea was possibly suggested by the term ‘analyticlevel’ that I had been using in previous works (e.g. Roncaglia 1990a: 264). Theterm ‘field of analysis’ is also better discarded, since it is commonly used for designatingsufficiently homogeneous sets of objects of analysis, while here we referto a technique of analysis, and specifically to the choices made in the process ofabstraction underlying any theoretical reasoning.28For an attempt along these lines, cf. Roncaglia (1995).