In commenting on a post, Marcel Proust [if only!] offers this observation:
“It has been roughly a quarter century since I last spent time thinking about Sraffa, but IIRC he demonstrated that one could speak equally well about the exploitation of any input to production, not just labor. My recollection is that he used the example of iron and showed how iron could be considered exploited. Again, IIRC, this was based on substituting an iron theory of value rather than a labor theory of value, the former as valid as the latter mathematically. Whatever good was used as the basis of value (labor or iron) would invariably be "exploited."”
Well, it was not Piero Sraffa who demonstrated that. It was I! Or more precisely, I proved it, unaware that a few years earlier, Josep Vegara, a Spanish economist, had also proved it. My proof appeared in an essay entitled “A Critique and Reinterpretation of Marx’s Labor Theory of Value,” published in the Spring 1981 issue of the journal Philosophy and Public Affairs. In a comment on my essay, the brilliant Marxist mathematical economist John Roemer noted that Vegara had proved the same theorem in his 1979 book Economia Politica y Modeles Multisectoriales [see pp. 56-7 of that work, for those interested.]
In my essay, I attempted an alternative mathematical analysis of Marx’s [correct] claim that capitalism rests on the exploitation of the working class. I was hopeful that Marxists mathematically abler than I would develop my ideas, but that has not happened, to the best of my knowledge.
I realize there is something pathetic about an eighty-five year old man tugging at people’s coat sleeves and saying, plaintively, “I did that, I did that, I really did that,” but inasmuch as this is the only thing I have ever proved in my entire life, I was seriously bummed by Roemer’s news.