[OPE-L:5542] Re: Humbug Aggregate Price-Value Correlations

Alejandro Valle Baeza (valle@servidor.unam.mx)
Sun, 28 Sep 1997 05:11:24 -0700 (PDT)

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On Wed, 24 Sep 1997, Paul Cockshott wrote:

> Alejandro Valle
> > The correlataion coeficient for Mexico in 1980 is about 0.83 without
> > reduction from complex to simple labor using wages and about 0.95 with
> > such reduction. The MAD for the same year is about 80%. The previous
> > figures does not consider productive labor and fixed capital problems.
> > This results, maybe, point out that correlation coeficient is not good
> > because of spurious correlation. I am not sure that 80% means that MTV
> > does not hold because there are many theoretical problems still unsolved,
> > as Lefteris pointed out. One important explanation for the impresive
> > magnitude of the MAD in Mexico is oil rent: the production cost is 2-3
> dol.
> > and the selling price is 15-16 $ per barrel. Hence there is a good reason
> > for high value price deviation in the Mexican economy. In fact, this is
> > the highest value-price deviation. I am sitll working on this.
> >
> Paul C
> The price value deviation for the oil sector is very high for Britain
> as well. Model A shows the measures for regression of labour values
> of industries against their prices including the oil industry, Model
> B excludes oil.
> Regression of prices against values for the UK in 1984
> ------------------------------------------------------
> measure Model A Model B
> 2
> R 0.955 0.976
> MeanAbsErr 13.5 %
> Max Error 157 %
> I do not consider that there exists a real problem of spurious
> correlation, for the reasons outlined by Allin, though I can
> accept that correlations, based as they are on an 'energy' or
> squared metric may be less appropriate for economic measures
> than a metric based on absolute deviation.

I will read Allin post on spurious correlation and will make some
comments then. As you know I have working with an alternative method for
measuring value-price deviations based on the correspondence between
direct labor and value added by industry. With my aproach it is possible
to obtain estimations of value price deviations for every year. I used
MAD and found tha it could be an important reduction on MAD by eliminating
oil industry and industries with very high taxes. I would like to see the
sensivity of oil industry for GB using MAD instead of r^2. Is it possible?

> By the way, I have just read your paper in Reasearch in Political
> Economy and find that I agree almost 100% with your approach to
> what value theory is about.

Thank you for this, I will apreciate any comment from you about this.

Un cordial saludo

Alejandro Valle