At the end of his contribution for The New Palgrave, Paul Samuelson (1987, p. 460) wrote:
Did any scholar have so great an impact on economic science as Piero Sraffa did in so few writings? One doubts it. And there cannot be many scholars in any field whose greatest works were published exclusively in their second half century of life. Piero Sraffa was much respected and much loved. With each passing year, economists perceive new grounds for admiring his genius.
Here Samuelson especially thought of Sraffa’s (1960) book Production of Commodities by Means of Commodities, « the best work that Piero Sraffa has bequeathed to economic science » (Samuelson 1998, p. 465). It was finally published in the year when Sraffa became 62, but its first ideas were developed before he was 30. Despite the extremely long gestation process of the book, the preface of the English edition referred to comments or help from only four persons: John Maynard Keynes, Abram Besicovitch, Frank Ramsey, and Alister Watson.
The Sraffa archives in the Wren Library (Trinity College, Cambridge, U.K.) reveal that a much longer list of names could have been produced, because many other scholars helped with the mathematics, or read the nearly final versions of the book. For example, Kurz and Salvadori (2001), in their well-documented study on Sraffa and the mathematicians, mention help from Peter Swinnerton-Dyer, John Arthur Todd, Bryan Birch, David Champernowne, Raffaele Mattioli, Sergio Steve, Paul Rosenstein-Rodan, Nicholas Kaldor, Pierangelo Garegnani, Maurice Dobb, Robert Neild, Amartya Sen, and Carlo Brunner…