Long-period Positions and Economic Change. A rejoinder

Roncaglia and Nell have criticised the interpretation of Sraffa's normal prices as centres of gravitation for actual prices. Roncaglia mainly focuses on the interpretation of the notion of gravitation in Smith and on the meaning of the ‘given outputs’ in Sraffa. Nell attempts to confine the relevance of Sraffa's theory to specific historical circumstances and to find a role for Sraffa's prices in his version of post-Keynesian price theory. This rejoinder criticises the case made by both Roncaglia and Nell, and defends Sraffa's centre of gravitation view.