Post-Modernism, Economics and Knowledge (Economics as Social Theory)

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Summary: Keynes's analysis of uncertainty is mathematical in nature
Review: This book of collected essays,edited by Cullenberg,Amariglio,and Ruccio,suffers from the same erroneous claims ,with respect to Keynes's work on uncertainty and the weight of the evidence ,that were published in a 2003 book edited by Ruccio and Amariglio,titled"Postmodern Moments in Modern Economics".The interested reader of this review will find a much more detailed review of the latter book which also applies to the current book under review.Keynes is not anti mathematical.Keynes's original anaysis of the concept of uncertainty takes place in chapters 26 and 29 of the A Treatise on Probability(TP)following an introductory analysis of the problem of the weight of the evidence in chapter 6 of the TP.Let w equal the weight of the evidence.Keynes defines w to be an element of the set [0,1].Keynes is thus the first scholar in history to define an index to measure w.Measuring w means to grade the strength or completeness of the relevant potential available evidence which a decision maker is going to use to make an estimate of probability.Now define u to measure uncertainty.Uncertainty is a function of the weight of the evidence.We obtain u=f(w).There is an inverse relationship between u and w.If w increases,uncertainty decreases.If w decreases,uncertainty increases.The case of risk requires a w equal to 1.u would then be equal to 0(no uncertainty).The case of total or complete uncertainty of the evidence(u=1) requires a w equal to zero.No probabilities of any type(point,interval,ordinal)can be calculated since there is no evidence upon which to estimate a probability.Keynes refers to this case as the case of ignorance on p.310 of the TP.It corresponds to a w=0(u=1).Keynes states that this extreme case is not the important one.The important case is where 0<w<1,the case of partial evidence.On p.240 of the General Theory(GT),Keynes states that uncertainty can be ranked.In his 1937 article in the Quarterly Journal of Economics(QJE),Keynes makes it clear that uncertainty can be graded(no uncertainty,little uncertainty, mild uncertainty,moderate uncertainty,severe uncertainty,acute uncertainty,great uncertainty and finally, complete or total uncertainty).Keynes gives an example of complete or total uncertainty in this article.It is the case of attempting to calculate probabilistically the position of wealthholders in New York in 1970 in 1937.Keynes correctly points out that "we simply do not know".Unfortunately,the editors of this book and the authors of the various essays have accepted the definition of uncertainty given by GLS Shackle,P Davidson and other Post Keynesians.This definition is that uncertainty is not a range.Uncertainty is the opposite of certainty.Thus,uncertainty can only mean complete or total uncertainty.This definition is nihilistic and directly contradicts the analysis of Keynes in the TP,GT and his 1937 QJE article.