multiplier-accelerator issue

["J. Barkley Rosser, Jr." <rosserjb@xxxxxxx>]

      I have just taken a look at some, but not all,
of the papers associated with the origins of the
multiplier-accelerator model (I do not have all of
them available at the moment, although I have
read most of them before).
     1)  The argument that Giblin invented the multiplier
looks to me to be a hard one to make, based on
reading his lecture.  It certainly is not the multiplier
as it is usually formulated, although there are hints
of it there, surely.  In any case, Giblin does not have
an accelerator model in his lecture that I could spot,
so he is not in the running on having developed the
multiplier-accelerator model.
     2)  Although one reads frequently that R.F. Kahn
"discovered" or "invented" the multiplier (according
to Keynes, anyway), I do not know where he published
that result, if he even did.
     3)  Although he did not work out a mathematical model,
J.M. Clark not only had the idea of the accelerator, but
understood that it was associated with a multiplier effect
as well prior to both Kalecki and Harrod.  The source
is J.M. Clark, "Capital Production and Consumer-taking:
A Further Word," Journal of Political Economy, Oct. 1932,
pp. 692-93.  In particular, although he sees an initiation
of a change in investment from a decrease in consumer
demand, he then notes that the decrease in investment,
"in turn reduces purchasing power, unless offset by opposite
movements elsewhere, and results in a positive decrease
in consumers' demand."
     If that is not the multiplier effect interacting with the
accelerator effect, I do not know what is.
     4)  The Kalecki model has certain mathematical problems.
It is a sort of multiplier-accelerator model, but not a full blown
one.
     5)  In his original paper in REStat in 1939, Samuelson
only mentions Alvin Hansen (who wrote in 1938) as an
influence on him.  He reiterates this in a piece in 1959
in REStat.  However, he discusses Harrod's role in his
less well known paper from later in that year, "A Synthesis
of the Principle of Acceleration and the Multiplier," Journal
of Political Economy, 1939, Dec. 1939, pp. 786-797.  He
provides the quote from Clark in there that I just noted.  He
gives a lot of credit to Harrod (and does not mention Kalecki),
but also declares that "Upon rigorous analysis his exposition
will be found to abound with non sequiturs and
oversimplifications. On the whole Harrod's intuition surpasses
his reasoned conclusions."
     In short, Harrod clearly played a very important role.  But,
he would appear to be neither the inventor of the idea of
combining a multiplier with an accelerator, credit for which
should probably go to J.M. Clark, nor of producing a fully
consistent and rigorous model that does so.
Barkley Rosser
James Madison University