I will argue that when Keynes states that, in general, probabilities are not susceptible to numerical estimation, he is arguing that the probabilities, in general, can’t be represented by single number answers or point estimates. But they can be represented by intervals. Keynes’s general...

Frank P Ramsey’s critique of Keynes’s logical Theory of Probability, presented in 1925 and published in 1930, is so weak and poor that J M Keynes or Bertrand Russell could easily have refuted and decimated Ramsey’s claims in the space of one half of an hour to one hour at Keynes’s...

This paper argues that a representation of the epistemic state of the individual through a non-additive measure provides a novel account of Keynes's view of probability theory proposed in the Treatise on Probability. The paper shows, first, that Keynes's non-numerical probabilities can be...

Keynes's initial, introductory presentation of his inexact measurement, approximation approach to interval valued probability occurred on pages 38-40 of chapter III of the A Treatise on Probability. Keynes used a simple diagram on page 38 to illustrate the non linear and non additive nature of...

Economists, working in the Heterodox schools of economics, have severely confused Keynes's interval valued probability–weight of the evidence approach to decision making from the A Treatise on Probability, that Keynes integrated into the General Theory by way of his definition of uncertainty...

The psychological basis for rank-dependent probability weighting, and for an inverse-S probability weighting function (PWF) in particular, has often been questioned. I examine the existence and shape of the PWF in a model allowing for optimism/pessimism over probability distributions and for...