[PEN-L:11433] Re: Intuition in Math Reasoning: Keynes & JM Clark

[Laurence Shute <lshute@xxxxxxxxxxxxx>]

In a 1941 letter to J.M. Clark, Keynes wrote:

"As you will have gathered the other evening, I agree with what you say
about the danger of a 'school,' even when it is one's own.  There is great
danger in quantitative forecasts which are based exclusively on statistics
relating to conditions by no means parallel.  I have tried to persuade
Gilbert and Humphrey and Salant that they should be more cautious.  I have
also tried to persuade them that they have tended to neglect certain
theoretical considerations which are important, in the interests of
simplifying their statistical task."

In Dec. 1941, before the AEA, J.M. Clark said:

"Among other things, we appear to be in for a period of government by
statistics and econometrics.  This is little better than chartless fumbling
with essentially quantitative [qualitative?] problems; ... There is real
danger that, in certain sectors, government's immediate objective will be
not a realistic picture of the lives of its citizens but figures in tables
or lines on charts which leave out vital imponderables and are not even
accurate as figures."

Larry Shute

Thanks for your message at 02:56 AM 7/23/97 -0700, romain_kroes.  Your
message was:
>It's relevant that Keynes doesn't condemn, here, the use of mathematics
>in economics (as for him, he rather liked to have recourse to them up to
>tautology), but that he implicitly accuses the lack of a conceptual
>basis in economics, so much so that "the back of the head" is nothing
>but a rough substitute for it.
>
>Economics aren't yet a true science, although such a tool has never been
>so necessary as nowadays. That's the reason why econometrics ask
>mathematics to fill the conceptual gap. This matter is economically the
>most important one, but I'm afraid it doesn't interest the most of
>economists...
>
>Sincerly
>
>Romain Kroes
>
>Laurence Shute wrote:
>>
>> Does this help any?  From the General Theory (pp 297-98):
>>
>> "It is a great fault of symbolic pseudo-mathematical methods of formalising
>> a system of economic analysis, such as we shall set down in section VI of
>> this chapter, that they expressly assume strict independence between the
>> factors involved and lose all their cogency and authority if this
>> hypothesis is disallowed; whereas, in ordinary discourse, where we are not
>> blindly manipulating but know all the time what we are doing and what the
>> words mean, we can keep 'at the back of our heads' the necessary reserves
>> and qualifications and the adjustments which we shall have to make later
>> on, in a way in which we cannot keep complicated partial differentials 'at
>> the back' of several pages of algebra which assume that they all vanish.
>> Too large a proportion of recent 'mathematical' economics are mere
>> concoctions, as imprecise as the initial assumptions they rest on, which
>> allow the author to lose4 sight of the complexities and interdependencies
>> of the real world in a maze of pretentious and unhelpful symbols."
>>
>> In 1940 Keynes was greatly worried that his American disciplices "were more
>> orthodox than the master," in the sense that they failed to keep the
>> necessary reservations "at the back of their head."
>
>