[OPE-L:5544] Re: Re: Re: William of Ockam's Razor and Political Economy

[Ajit Sinha <ajitsinha@xxxxxxxxxxxxxxx>]

Allin Cottrell wrote:

> On Thu, 10 May 2001, Gerald_A_Levy wrote:
>
> > Re Paul C's [5533]:
> >
> > > Without a causal and hence predictive theory
> > > of price one can have no basis for the theory
> > > of relative surplus value, to take just one
> > > instance from Marx's work. I could equally
> > > well have said no theory of differential ground
> > > rent...
>
> > All of the above identifies a causal theory with a predictive one.
> > One can, however, have a theory in which causal relationships are
> > identified but (e.g. because of the quantity of unknowns) one
> > which does not claim to be predictive.
>
> I think this is a misunderstanding.  A causal theory is capable of
> generating predictions _conditional_ on knowledge of the values of the
> theory's "independent variables".  If these values aren't in fact
> known then one can't make _actual_ predictions, but that doesn't mean
> the theory is non-predictive in the sense Paul is using.
>
> Allin.

_____________________

I think the author to whom Allin is responding is confusing prediction
with forcasting. Every causal theory must predict. Prediction is an
essential aspect of the structure of a causal theory. However, and this
may come as a surprise to many, I think Sraffa's PCMC is a thorough
critique of mechanical causality in economic theory. His arguments are
like theorems of geometry, which are not causal but rather propositions of
essential relations. Cheers, ajit sinha