Adam Smith y su 'effectual demand'

Un día como hoy, en 1723, nació Adam Smith, es por ello que trataremos un aspecto puntual de su teoría económica, su concepto de demanda "effectual" (effectual suele traducirse al español como efectiva, pero, por razones que se verán más adelante, no nos contentaremos con dicha traducción, conservando el vocablo original).

Es en el capítulo 7 de la Riqueza de las Naciones donde Smith introduce el concepto de demanda "effectual", que es la demanda existente para una mercancía correspondiente a su precio natural. Veamos la siguiente cita de Smith Adam, An Inquiry into the nature and causes of the Wealth of Nations", edited by Edwin Cannan, The Modern Library, New York.

"the demand of those who are willing to pay the natural price of the commodity...Such people may be called the effectual demanders, and their demand the effectual demand; since it may be sufficient to effectuate the bringing of the commodity to market." p. 56

Dado que ésta demanda, a precios naturales, es referida para cada distinta mercancía, no idéntica a el concepto macroeconómico de demanda efectiva, lo que si puede decirse es que es su equivalente microeconómico.

Ahora bien, el rol de la demanda "effectual" se ve claramente si se distingue, como lo hace Smith, entre precios de mercado y precios naturales, acerca de éstos últimos:

"When the price of any commodity is neither more nor less than what is sufficient to pay the rent of the land, the wages of the labour, and the profits of the stock employed in raising, preparing, and bringing it to market, according to their natural rates, the commodity is then sold for what may be its natural price." p. 55

Sobre los precios de mercado, que aquellos a los cuales se vende una mercancía; estos precios pueden o no coincidir. El mecanismo persistente (véase aquí sobre el concepto de persistencia) en una economía capitalista que impulsa hacia la coincidencia de ambos precios puede verse a partir de lo siguiente:

"The market price of every particular commodity is regulated by the proportion between the quantity which is actually brought to market, and the demand of those who are willing to pay the natural price of the commodity" p. 56

No se le menciona explícitamente, pero es el mecanismo de la competencia de capitales actuando a través de los movimientos de capital para que la cantidad llevada al mercado (quantity actually brought to market) tienda a coincidir con aquella correspondiente a la demanda "effectual".

Si la competencia de capitales fuera la única fuerza existente en el tiempo, o si las fuerzas extrañas a ésta se anularan entre sí, entonces llegaríamos a lo siguiente:

"The whole quantity of industry annually employed in order to bring any commodity to market, naturally suits itself in this manner to effectual demand." p. 58

Para seguir avanzando, cabe hacer notar que hemos utilizado el concepto de precios naturales porque A. Smith los contiene en una visión donde éstos resultan de la simple suma de componentes; lo cual incurre en un error por insuficiencia teórica, pues es necesario analizar relaciones entre tasas distributivas (incluyendo relación inversa salarios-ganancias), así como proporciones en el input, en última instancia ello implica seguir a Ricardo y culminar con la determinación de precios de producción de Piero Sraffa (sobre Sraffa y precios de producción ver ésta entrada previa en nuestro blog). A partir de ahora, al tratar la demanda "effectual", la categoría de precios de producción sustituye al precio natural, lo cual no representa ningún problema.

La aplicación del anterior mecanismo no implica validar una interpretación de que hay en A. Smith una determinación de precios de largo plazo por la vía de oferta y demanda; los precios de producción (que son de largo plazo) se determinan aparte, dependiendo de las proporciones en el input (que a su vez dependen del estado tecnológico) y de las variables distributivas (una de ella determinada a nivel exógeno al sistema económico), en palabras de Pierangelo Garegnani afirma en The classical theory of wages and the role of demand schedules in the determination of relative prices, American Economic Review, Vol. 73, #2:

"The role of effectual demand is to explain the tendency of the 'actual' or market price toward the normal price and not that of determining the latter" p. 312

Si bien la determinación del producto (a través de la demanda efectiva en teorías sraffianas modernas) entra como dato en la determinación de los precios de producción, la distinción que hicimos anteriormente entre demanda "effectual" y demanda efectiva muestra su utilidad. Ya que, al referirse la demanda "effectual" a mercancías específicas, no es determinante en sí del nivel del producto, sino que simplemente lleva a modificar la composición de éste durante su impulso a que los precios de mercado tiendan a los precios de producción. No hay contradicción en la teoría, más bien hay rigor de sobra.

Una última aclaración, Alessandro Roncaglia utiliza el concepto de demanda "effectual" para afirmar un análisis económico 'momento a momento', no uno de largo plazo; regresemos pues a Garegnani, quien en el mismo paper afirma sobre la demanda "effectual":

"It does not therefore consist of a curve but of a single determinate price-quantity point" p. 312

Si bien dicho punto precio-cantidad al que corresponde la demanda "effectual" puede ser distinto a lo largo del tiempo, no implica per se que el análisis clásico sea uno de momento a momento, simplemente por el hecho de que precios y cantidades tienen una determinación distinta para los clásicos (algo que el mismo Roncaglia acepta), dada esa distinta determinación, podemos tener en distintos momentos distinta demanda "effectual" para un mismo precio de producción, éste último siendo uno de largo plazo, no un precio de producción de momento a momento.

Las notas anteriores pretenden, además de recordar a Adam Smith en un día que es pertinente hacerlo, recuperar un concepto poco difundido de su obra, concepto que es sumamente útil para el estudio de la economía, la demanda "effectual", asimismo, hemos intentado aclarar algunas discusiones y confusiones alrededor de dicho concepto, esperemos sean de utilidad.

El camino del economista, Sraffa (1)

La presente sección, el camino del economista, básicamente consistirá en presentar síntesis y/o reflexiones de algunas lecturas que vaya realizando, presentando así, el camino del economista.

Por razones extraordinarias, presentaré éste texto primeramente en inglés, pero pronto pondré la versión en español (se infiere de ello que a partir de ahora, se buscará que éste blog sea bilingüe).

The following text presents the impressions of an undergraduate student in economics (me) of Piero Sraffa's book, Production of Commodities by Means of Commodities. Until now I have read the preface and the first 3 chapters.

The preface presents us the object of investigation and some important assumptions in a way that's very straightforward:

"No changes in output and (at any rate in Parts I and II) no changes in proportions in which different means of production are used by an industry are considered, so that no question arises as to the variation or constancy of returns. The investigation is concerned exclusively with such properties of an economic system as do not depend on changes in the scale of production or in the proportions of 'factors'." p.v

Since, as we progress further in the book, the economic system we analyse will produce a surpuls to be distributed, we can only conclude, that to have a positive net product (net product>1), no changes in proportions are needed; this does not means that Sraffa rejects that in economic reality these changes occur, neither he denies that such changes affect economic relations, but he do recognises that a surplus exists, even in their absence.

To continue, in chapter 1, we find ourselves in front of an economic system that produces just for subsistence, the key aspect here is that, in order for this economic system -which produces no surplus yet- to keep functioning, the produced commodities must re-enter the next production process in the same exact quantity that they entered the previous one, to achieve this, there exists only one set of prices -called exchange values by Sraffa-, "such values spring directly from the methods of production." p. 3

Let's keep this in mind as we keep on advancing: prices do not emerge from supply and demand, but from methods of production.

However, when we do have a surplus, a new feature comes into scene, "the surplus (or profit) must be distributed in proportion to the means of production (capital) advanced in each industry; and such a proportion between two aggregates of heterogeneous goods (in other words, the rate of profits) cannot be determined before we know the prices of the goods...The result is that the distribution of the surplus must be determined through the same mechanism and at the same time as are the prices of the commodities." p. 6

In the previous paragrapgh, a hint towards what we know the capital controversies can be seen; also, and most importantly, because of this simultaneous determination, we can see how the system opens itself to socio-institutional closure (see 1) (see 2).

Something which drew my attention, and cannot fully explain, is that the rate of profits "must be uniform for all industries" p. 6

This chapter also presents us with a distinction of commodities in two categories, those that enter into the production of all commodities are called basic commodities, and those that don't, are called non-basic commodities.

Another distinction, in this case about the wage, is included in this chapter; it is recognised that wages can have a share of the surplus, hence, being more than those of subsistence, following this, the surplus wage can be considered a variable element, in spite of this recognition, Sraffa tells us "We shall, nevertheless, refrain in this book from tampering with the traditional wage concept and shall follow the usual practice of treating the whole of the wage as variable" p. 10

This results in having "the necessaries of consumption" (goods the workers consume) as non-basics; so, in the system, taking the place of quantities of subsistence, we have quantities of labour employed.

Once having this explicited in chapter 2, the next chapter begins by posing the question of what happens when wages are reduced (not necessarily as to met their subsistence level).

We see that if proportion between labour and means of production is the same through all industries, in other words, if we have the same methods of production, then a change in the wage won't change prices; let's see this from another position, the position where proportions are unequal, in this case, because of some industries having less labour employed in respect to capital, what is paid less because of wages is not enough for to cover extra payments of benefit (and viceversa when proportions are the other way). Seeing that unequal proportions divide industries into 2 groups, they're called deficit industries and surplus industries, this division being made "It follows that, with a wage-reduction, price-changes would be called for to redress the balance in each of the 'deficit' and in each of the 'surplus' industries" p. 14

One might think that the previous argument is enough, but it isn't, Sraffa goes further and he explains that, in order to see how prices move, we must not only take into account the proportions between labour and means of productions in every industry, we must recognise that these industries use means of production which were also produced by means of a prior combination of labour and means of production, this affecting price determination, in other words, "the relative price-movements of two products come to depend, not only on the 'proportions' of labour to means of production by which they are respectedly produced, but also on the 'proportions' by which those means have themselves been produced" p. 15

Hence, we now have commodities produced by commodities.

Given the inequality of proportions between industries, we could still talk about the existence of a critical proportion dividing the two types of industries, this proportion would be one that if it existed in one industry, such an industry would not see its price affected by changes in distributive variables (this industry would also need, in order to be a critical industry, to have all its means of production made by processes which used the same critical proportion). Important is to notice that we are not claiming that the prices of such an industry would be invariant to changes in proportions used, here we must remember the key assumption presented in the preface.

It is precisely the topic if this proportion the one that closes the third chapter.

"It follows that the only 'value-ratio' which can be invariant to changes in the wage, and therefore is capable of being 'recurrent' in the sense defined in s21, is the one that is equal to the rate of profits which correspond to zero wage. And that is the 'balancing' ratio.

We shall call Maximum rate of profits the rate of profits as it would be if the whole of the national income went to profits. And we shall denote by a single letter, R, the two coincident ratios" p. 17

One final note, in the following quote I think there is neither an explicit nor implicit assumption about demand (leaving it as an open issue), but I cannot see if the same happens about competition, in other words, does the following paragraph includes an underlying assumption about competition?

"A further effect of the rise in the price of the product would of course be to help a given quantity of product to go a longer way towards achieving the required rate of profit" p. 14

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16/02/2012

Further notes:

1.- I think I have found a tentative answer about my doubt of the uniform rate throughout all industries, this must happen because we are in a competitive context.

2.- The classical notion of competition is quite different from the marginalist notion, this must be taken into account in order to avoid understanding incorrectly when I speak about competition, my next post should cover that up.