Monday 23 July 2012

Abstract Labour

The concept of Abstract Labour, and of Abstract Labour-time, is fundamental to Marx's theory of measurable value. That is why it has been a matter of considerable debate. Prima facie, the concept is straightforward. Marx's Labour Theory of Value is based on the notion that Value is objectively measurable, in terms of the labour-time required for production. However, because, obviously, not all Labour is the same, e.g. the labour of a tailor is not the same as that of a weaver, Marx distinguishes between these particular types of labour, that he calls Concrete labour, and Abstract Labour. Abstract Labour, he says is labour stripped of all the particularities of concrete labour. It is human labour in general.

For an initial understanding of Marx's economic theory, this definition suffices. However, a little consideration leads us to see that there are problems with this definition, which is why there has been controversy over it, not just from opponents of Marx, but within the ranks of Marxist economists themselves. On the one hand, the easiest way to think of what Marx means, when he talks about Abstract Labour, as Labour with all the peculiarities of concrete labour stripped away, is to think about similar examples. So, for example, the measurement of distance, that we call a foot, originated in the fact that, once, distances were measured out using human feet – indeed, many measures are based on lengths of human body parts. Once it became necessary to have not only more accurate, but standardised measurements of distance, the problem of using “concrete” human feet becomes obvious, and so an “abstract” foot is developed, which is a fixed length.

So, we can think of an hour of Abstract Labour-time in a similar way, but when we do that it then begs many more questions. Exactly, how is this hour of Abstract Labour-time to be decided upon, how is it to be fixed, should it be fixed and so on? Many of these questions are complicated by the fact that Marx himself seems to describe Abstract Labour differently, in various places in Capital. So, for example, he describes Abstract Labour as above, but he also talks about Abstract Labour in terms of being the average of all concrete labour, and an hour of average abstract labour-time being the equivalent of all of social production, divided by the total number of hours of concrete social labour expended to produce it. Elsewhere, he identifies Abstract Labour with the kind of simple, unskilled labour that, he argues, Capitalism was driving all Labour towards. It is he says, that labour, which any human being could perform, requiring only the use of normal muscles, intelligence and so on. But, what is that? The average intelligence today is not what it was 100 years ago. On the other hand, the average person today would be unable to perform the average level of exertion of an unskilled labourer, like a Navvie, from 100 years ago.

If we constantly adjust this kind of measurement of Abstract labour-time, then not only does it mean that the measurement of Value is constantly moving, but it means that Abstract Labour is different in different places at the same time. That would be like changing the physical length of “the foot” as a measurement, every time human feet themselves changed in size!  The problem can be explained like this.  Suppose we have a society where all the Labour is perfectly homogeneous, so it all equals Abstract Labour.  It produces clay pots.  It takes 1 hour of its Labour-time to produce a pot.  Twenty years later, the technology for producing pots is exactly the same.  However, as a result of all workers gaining experience, in pot making, and as a result of every worker benefiting from the lessons handed down to them by the previous generation, the pots now made are of considerably higher quality than in the earlier period.  If one of these pots is then compared with the older pots, the producer of the older pot would recognise the higher quality, and the quality of the labour that went into it.  Although, it might take only 1 hour of Labour-time of these later workers to produce this higher quality pot, the producer of the earlier pot, recognising the higher quality of the labour that went to produce it, might be prepared to exchange two of their pots for it!  Yet, within the same society, we are comparing Abstract Labour-time in both cases.

The question is further complicated by the fact that Marx in Chapter 1 of Capital Volume I, also says that just as the money commodity comes to be the manifestation of Value (Abstract Labour-time), so the concrete labour used to produce the Money Commodity comes to be the manifestation of Abstract Labour.

Now none of these private labours in its natural form possesses this specifically social form of abstract human labour, just as little as the commodity in its natural form possesses the social form of mere coagulation of labour, or value. However, through the fact that the natural form of a commodity (linen, in this case) becomes a universal Equivalent-form because all other commodities relate themselves to this natural form as the appearance-form of their own value, hence linen-weaving also turns into a universal form of realization of abstract human labour or into labour of immediately social form... Since they are not-immediately social labour, in the first place the social form is a form which differs from the natural forms of the real, useful labours and is foreign to them and abstract; and in the second place, all kinds of private labour obtain their social character only in a contradictory way, by all being equated to one exclusive kind of private labour (linen-weaving, in this case). This latter thereby becomes the immediate and universal form of appearance of abstract human labour and thereby labour in immediately social form. It manifests itself consequently also in a product which is socially valid and universally exchangeable.”

However, there seems a problem to me of using the concrete labour involved in the production of the Money Commodity. For one thing, its not homogeneous. Secondly, it changes, over time and place, as much as any other kind of concrete labour. Thirdly, because it is concrete labour, it could be skilled, in which case, other unskilled concrete labours would have to be assessed as only fractions of an hour of Abstract Labour (not that there is anything technically wrong with that).

Given that science, in the area of the physical sciences, in particular, has moved to ever more precise definitions of the metrics it uses, and ever more accurate measurement of them, it seems to me that a theory of Objective Value has to do likewise. None of the objections to the concept of Abstract Labour invalidate it, or thereby undermine the Labour Theory of Value. For, a theoretical understanding of that theory, the concept of Abstract Labour will suffice. But, it is in my opinion necessary to resolve this matter by establishing a precise definition of Abstract Labour, and a precise and fixed measurement of an Abstract Labour Hour, as the metric by which Value is measured. One way to do that would be to use Marx's method of taking all social production at a given moment in time, and dividing it by the total amount of social labour used in its production, and then reduce this down to that labour which produces the least Value, setting that as 1, and all other concrete labour as multiples of it.

Similarly, all future labour can be compared with, and measured against this labour, in the way that Marx does by measuring its worth according to the Value of its output. A further discussion of Abstract Labour can also be found at:





31 comments:

Link said...

Boffy,

You are needlessly complicating Abstract Labor.

Let us look at at the supposed discrepancies in Marx's definition(s)

Once it became necessary to have not only more accurate, but standardised measurements of distance the problem of using “concrete” human feet becomes obvious, and so an “abstract” foot is developed, which is a fixed length.

You are fixating on the fact that the standard for length must be "fixed" and assuming therefore that Abstract Labor must also have a fixed (=immutable?) standard.

That is NOT what Marx argues, at least not about Abstract Labor.

Instead, this part of the argument simply informs us that the standard cannot conform to any specific concrete example (or if it does it is incidental).

Therefore, the standard must be ABSTRACT rather than concrete.

If anything, the foot as a measure of length (and, notably, this is NOT universally adopted) corresponds much closer to the FORM of value, Exchange Value, than it does to Value. Exchange Value is basically about units and commensurability.

he also talks about Abstract Labour in terms of being the average of all concrete labour, and an hour of average abstract labour-time being the equivalent of all of social production, divided by the total number of hours of concrete social labour expended to produce it.

It is better to say that Abstract Labor equates to Concrete Labor in the aggregate measured in time (social production). For the most part, Abstract Labor is defined through the actual process of abstraction from concrete labor -- and the fact that is SOCIAL (but here we are assuming it to be social). But this is the equation that maps it back from abstract to concrete.

Elsewhere, he identifies Abstract Labour with the kind of simple, unskilled labour that he argues, Capitalism was driving all Labour towards. It is he says, that labour, which any human being could perform, requiring only the use of normal, muscles, intelligence and so on.

This is not a definition of Abstract Labor but rather a defining of its fundamental unit. Note that this conflicts with your statement above that abstract labor time is associated with the average hour of concrete labor employed in social production.

The question is further complicated by the fact that Marx in Chapter 1 of Capital Volume I, also says that just as the money commodity comes to be the manifestation of Value (Abstract Labour-time), so the concrete labour used to produce the Money Commodity comes to be the manifestation of Abstract Labour.

The concrete labor used to produce money comes to be the universal MEASURE of Abstract Labor (which you could map to the "foot" in length). Of course this in turn becomes treated as a universal manifestation. However, as Marx's quote elaborates, this function is filled by money not out of theoretical necessity but out of practical demand. Thus linen does not assume the role because its qualities are inferior for this role vs gold/precious metals.

Boffy said...

Thank you for your comment. I don't think I am needlessly complicating Abstract Labour. I think that the category is itself complicated, which is why there has been so much discussion and dispute over it, for example, as set out in the link to the Rubin School.

I take your point about the difference between Abstract Labour, and an hour of Abstract Labour as a unit of measurement, but surely in order to determine an hour of Abstract Labour as such a measurement, it is necessary to determine what you mean exactly by Abstract Labour.

In other words, is Abstract Labour merely an abstraction from all concrete Labour which still leaves it essentially undefined, it simply tells us what it is not; is it essentially nothing but the average of all social labour at any one time, in which case the content of an hour of Abstract Labour changes over time, and thereby makes it impossible to compare a quantum of Value in t' compared to t''; or is it equal to simple labour, i.e. that labour which every individual can perform, which has the problem I set out, which is that this in itself changes over time, and is in any case ill-defined; or is it, as Marx arrives at finally defined by that Labour, which produces the money commodity. The problem with the latter being that in an economy in which Prices of Production have replaced Exchange Values, the latter is indeterminate.

As a recent UK TV programme about measurement demonstrated there are problems with all forms of measurement, be they of length, time, weight etc. and the measurement of Value is no different.

However, in all of the rest of science there has been increasing definition and precision in the units of measurement, and therefore in the accuracy with which science can undertake its analysis. Marxists should be no less concerned to ensure that the basic unit of measurement for our science - Value - is subject to the same kind of rigour and evaluation.

Unknown said...

Hello Boffy,


About abstract labour you say:

“…One way to do that would be to use Marx's method of taking all social production at a given moment in time, and dividing it by the total amount of social labour used in its production, and then reduce this down to that labour which produces the least Value, setting that as 1, and all other concrete labour [This is how competition turns all concrete labour into abstract labour] as multiples of it…”
(Boffy)

I don’t see how abstract labour as you want it is different. I don’t see how abstract labour as you want it is new.

Please excuse me for putting in the words in the square brackets […]

Thank you for the work that you put into making this Blog.

Boffy said...

Its the difference between abstract labour and simple labour. Abstract labour as the name suggests is not some specific concrete labour, but labour as merely an abstraction, a concept. For example, I might have as a concept of measuring length a foot, because in the past when precision was not that vital, using a human foot was one way of comparing the length of one thing to another. But, when it comes to actually measuring something with more precision, a concrete human foot is no use, because they vary in size. Its necessary to settle on some actual length to represent the metric "foot" in general. In other words, an abstract foot, which may not actually exist as a real human foot anywhere.

Now, as merely a unit of measurement, it does not matter how long this abstract foot is, provided that it is used consistently as the unit of measurement. I might, for example choose, the largest human feet as the basis for determining an abstract foot, in which case most actual human feet would be smaller than this abstract foot, and vice versa.

In Capital I, and elsewhere, Marx says that once a money commodity is developed as the general commodity it thereby becomes the means of measuring value, via the value form, as exchange value, as the universal equivalent form of value. But, that means, he says, that the labour involved in producing this money commodity now likewise becomes the general form of labour, abstract labour, that represents all other labour.

But, logically, there is no reason why this abstract labour, involved in producing the money commodity - say gold - has to be the kind of concrete labour that produces the least value, anymore than the actual length of an abstract foot, decided upon as a unit of measurement, has to be based upon the smallest human feet, rather than the largest human feet.

Suppose, one hour of labour employed in gold mining produces 10 grams of gold, and one hour of labour employed in cotton spinning, produces 1 kilo of yarn. The 1 kilo of yarn will only exchange for 10 grams of gold, if (ignoring the value of constant capital) the labour in both spheres produces the same amount of value. But, there is no reason why this should be, and that is because, as Marx says, this abstract labour may also be simple or complex.

Suppose, 10 grams of gold exchanges for 2 kilos of yarn. In that case, one hour of labour employed in gold producing, i.e. what has now become abstract labour producing the general commodity, produces twice as much value as that employed in cotton spinning. Abstract labour would then represent complex labour, whilst the simple labour employed in cotton spinning would produce only a fraction of an hour of abstract labour.

However, its usually assumed that simple labour is taken as the base measurement, i.e. as 1, and that complex labour then represents multiples of it. There is no reason why this has to be the case. In Capital 1, for example, Marx discusses various instances where the labour actually provided by individual workers produces less than the average amount of value produced by other workers of the same type.

Unknown said...

Sorry to dwell on same point.

It is a key point.

An hour remained an hour e.g. after the introduction of power looms into England. But still we do not use the same abstract labour hour after the change which we used before it. We use a fresh abstract labour hour. It is not the same. I mean apart from the hour remaining an hour the abstract labour all changes. It is changing. Marx speaks of: “… normal conditions of production and with the average degree of skill and intensity prevalent at the time…”

And yes we can speak of skilled labour that counts for more than simple labour. In the same way a foot counts for exactly 12x an inch. But it’s wrong to speak of skilled abstract labour. It’s like speaking of feet after we just reduced them to inches.

“…For simplicity's sake we shall henceforth account every kind of labour to be unskilled, simple labour; by this we do no more than save ourselves the trouble of making the reduction…”
(Marx)
http://www.econlib.org/library/YPDBooks/Marx/mrxCpA1.html#anchor_n23

Here’s a miner:

He says:

10 grams of gold is worth more than a kilo of yarn.

But spinner answers:

A kilo of yarn is worth more than 10 grams of gold.

After a long time they finally agree:

Miner says: 10 grams of gold is worth a kilo of yarn,
Spinner says: a kilo of yarn is worth 10 grams of gold.

So we get:

10 grams of gold is worth a kilo of yarn.
A kilo of yarn is worth 10 grams of gold.

We have 2 lines. Gold and the yarn recur in the second line as chance would have it the opposite way around.

We can simplify:

A kilo of yarn is worth 10 grams of gold.

Just as chance would have it we now have the gold and the yarn this way around. This way around the yarn acts as what Marx calls the relative form. And this way around the gold acts as what Marx calls the equivalent form. Here the equivalent form is not as yet money. To be money gold would first need to pass through some more steps to become the universal equivalent to all other commodities. But now for us here and for the moment gold happens to be acting as the equivalent for the yarn only. This also means that the yarn is acting as the relative for the gold.

Quality and Quantity

To reckon in quantities always is to adopt some same qualitative unit. To borrow Marx’ example: The miner balances his gold by 10 grams of brass weight. The brass is acting only as weight absolutely nothing else for now. Only in this one same natural quality of having weight does the brass equal the gold.

Well then, in:

A kilo of yarn is worth 10 grams of gold.

So now the gold is acting just as labour as defined above, absolutely nothing else for now. Only in having this one same social quality of abstract labour does the gold equal the yarn.

This perhaps covered your point?

Boffy said...

You are still confusing and conflating abstract labour with simple labour. The point I have set out above illustrates that if, as Marx says, the labour involved in gold mining becomes the proxy for abstract labour once gold becomes the money commodity, and this money commodity becomes the measure of value, there is no reason why this abstract labour, i.e. gold mining labour, has also to be simple labour. An hour of this gold mining labour, which is now the proxy for "abstract labour", can just as easily be equal to 2 hours of labour employed in spinning.

In that case, the spinning labour would be simple labour, and the abstract labour proxy - gold mining labour - would be complex labour. One hour of simple labour (spinning) would be equal to 0.5 hours of abstract labour, whilst 1 hour of gold mining labour, as the proxy for abstract labour, is by definition equal to 1 hour of abstract labour.

Incidentally, its also wrong to identify "skilled" labour with "complex" labour. As Marx describes in Capital I, whether labour is considered simple or complex and to what extent some specific labour is a multiple of simple labour can only be determined post facto, in the market, as a consequence of what consumers are prepared to pay for the product of each type of concrete labour.

There is also an error in your comments about abstract labour and value in relation to weaving before and after the introduction of power looms. The hand loom weaver might say produce 10 metres of cloth in 100 hours of labour. Once power looms are introduced, it becomes possible to produce 100 metres of cloth in 100 hours.

In the first case a metre of cloth has a value of 10 hours, and in the second case it has a value of 1 hour. Marx makes clear that in terms of the individual value of each this remains the case. The individual value of the hand loom weavers 10 metres of cloth remains 10 hours per metre, whereas the individual value of the 100 metres of cloth of the power loom weaver is 1 hour per metre. In each hour, the hand loom weaver and the power loom weaver both produce the same amount of value, but this value is embodied in completely different quantities of use values - the 1 hour of value produced by the latter is embodied in ten times as many use values as the former, which is why the individual value per metre, is only a tenth of that of the former.

This is central to marx's analysis of rent, for example, where he describes precisely this point that on different qualities of land, one amount of capital and labour, produces the same amount of value, but this value is contained in totally different quantities of output. It is the difference in the individual value of each type of output that leads to surplus profits and rent.

Returning to the hand loom weaver and the power loom weaver, the individual value of a metre of output of the former is 10 hours, whereas the latter it is just 1 hour. But, both sell their output at the market value, the social value of this commodity. As its likely that the power loom weaver's output will dominate the market, it is likely that they will determine the market value of cloth.

In 100 hours they will continue to produce 100 hours of value, and this will be contained in 100 metres of cloth. If we say that 1 hour of labour is equal to £1, cloth will sell at £1 per metre. The power loom weaver will sell their output for £1 per metre, and so will the hand loom weaver. The difference being that the individual value of the hand loom weaver's output is £10 per metre, which means they would sell their output for a tenth of its individual value. That is exactly why the hand loom weavers fell into such terrible conditions after power looms were introduced.

Unknown said...

You say:

“… Incidentally, its also wrong to identify "skilled" labour with "complex" labour. As Marx describes in Capital I, whether labour is considered simple or complex and to what extent some specific labour is a multiple of simple labour can only be determined post facto, in the market, as a consequence of what consumers are prepared to pay for the product of each type of concrete labour…”
(Boffy)

But the question is what do the prices which the consumers are prepared to pay for the products depend on?

You have the hand-loom weaver weaving for 100 hours by hand to make 10 meters of cloth. Then you say:

“… In the first case a metre of cloth has a value of 10 hours…”
(Boffy)

No. The weaver added 10 hours to the values in the means of production used up. So whatever values the cloth has should be more than just 10 hours.

But our big question here is:

What’s the difference between labour in its role in producing use-values and in its role in producing values?

“… On the one hand all labour is, speaking physiologically, an expenditure of human labour-power, and in its character of identical abstract human labour, it creates and forms the value of commodities. On the other hand, all labour is the expenditure of human labour-power in a special form and with a definite aim, and in this, its character of concrete useful labour, it produces use-values…“
(Marx)
http://www.econlib.org/library/YPDBooks/Marx/mrxCpA1.html#I.I.34

After the introduction of power looms into England how many hours did the hand-loom weaver put in per day? In the role in producing use-values he put in up to 20 hours per day. But in the role in producing values he put in about 10 hours per day. How so? That’s because in the new conditions his 20 hours counted as just 10 hours of abstract labour.

Take money out of the equation (till later) and it’s just the same with our miner above. He has 10 grams of gold. How many hours did he put into it? In the role in producing use-values he may have put next to nothing into it. Or he may have put whole years of labour of great skill and worn out costly products of labour (means of production). But we must admit that in exchange it is indistinguishable from the x hours of abstract labour in a kilo of yarn:

10 grams of gold is worth a kilo of yarn.
A kilo of yarn is worth 10 grams of gold.

How is the gold indistinguishable?

Is it indistinguishable in labour in its role in producing use-values?

No.

But it is indistinguishable only in labour in its role in producing values.

Boffy said...

Thank you for your further comments.

In determining what consumers are prepared for one type of labour as opposed to another - the spinner's labour as opposed to the gold miner's labour, I followed Marx's method of setting the value of constant capital (means of production)to zero, so that it is only the value created by labour that is being compared. The question asked is not as you put it, "what do the prices which the consumers are prepared to pay for the products depend on", but how much do consumers value the product of one type of labour compared to another.

I'm afraid that your comments in relation to use value as values are very confused, and I do not have the time here to correct them. I would suggest reading my definitions of use value and value, contained in my Glossary of Marxist terms. For now I will just make these brief points.

The way to determine the value created by the labour is how much the consumer is prepared to pay for their product. The consumer does not distinguish between a metre of linen produced by a power loom weaver, and that produced by a hand loom weaver. To the extent they might do so, they might actually value the latter more highly, to the extent that having been produced by a skilled craftsmen it may be considered higher quality, and containing greater use value. But, setting that aside, the consumer determines the value produced by an hour of weaving labour compared to an hour of gold mining labour by the product of that labour in either case, whether the weaving labour uses a hand-loom or a power loom.

As Marx points out no additional labour is required to preserve the value already in the means of production. If the 100 metres of yarn used by the weaver has a value of £10, this value is preserved by the action of concrete weaving labour upon it, whether this labour is undertaken for 10 hours by a hand loom weaver, or one hour by a power loom weaver.

Its not that the labour of the hand-loom weaver counts as only 10 hours of abstract labour after the introduction of power looms. As Marx makes clear, in terms of the individual value produced by this labour, it would continue to be 20 hours, and this individual value is embodied in the output produced by the hand-loom weaver. But, this is precisely the point that Marx makes against Smith and Ricardo. They had an embodied labour theory of value, which leads them into error, such as those you are making here.

As soon as commodity production and exchange takes place on a large scale, the exchange value of commodities is determined by their market value, by the socially necessary labour required for their reproduction. I have set this out in my post on "Individual Value" and elsewhere. The socially necessary labour-time is the aggregate of all of these individual values.

If power looms were used in the production of only a small proportion of the output of cloth, the market value would be dominated by the value of hand-loom production. In that case, as Marx sets out in Capital I, in discussing international comparisons of wages, and the effects of the introduction of machinery, it then becomes as though the labour employed using the power looms is complex labour, whilst the labour employed using hand looms is simple labour.

But, this is a different question as to whether any of this labour is equal to abstract labour. In other words, an hour of concrete labour by a hand-loom weaver, may be equal to 2 hours of abstract labour (now represented by its proxy, gold mining labour). If the weaving labour employed by a particular firm uses a machine that raises its productivity to ten times that of the hand-loom weaver, it may then produce the equivalent of 20 hours of abstract labour for every hour worked.

In that case, each hour of concrete labour by the hand-loom weaver would produce the equivalent of 2 hours of gold-mining (abstract) labour, whereas every hour of concrete labour by the power loom worker would produce the equivalent of 20 hours of gold-mining (abstract) labour.

Unknown said...

Thank you,

Please feel free to answer just as you find time and want to.

For my previous reply I found my perfect quote to say just what I also said to you. That quote seemed long to use. Now I’ve found this shorter one. It says the same:

“…When, in England, the power-loom came to compete with the hand-loom, only half the former time of labour was wanted to convert a given amount of yarn into a yard of cotton or cloth. The poor hand-loom weaver now worked seventeen or eighteen hours daily, instead of the nine or ten hours he had worked before. Still the product of twenty hours of his labour represented now only ten social hours of labour, or ten hours of labour socially necessary for the conversion of a certain amount of yarn into textile stuffs. His product of twenty hours had, therefore, no more value than his former product of ten hours…”
(Marx)
https://www.marxists.org/archive/marx/works/1865/value-price-profit/ch02.htm#c6

Still not sure how you reckon that confused about use-value .

Unknown said...

And on skilled labour you say that: “…consumers value the product of one type of labour compared to another…”

Why do consumers value the product of one type of labour compared to another? What changes their minds?

You say: “…no additional labour is required to preserve the value already in the means of production…”

Nowhere did I claim that. But I just said that the hand-loom weaver adds value to his means of production…

Let me try to get to all details one-by-one. But I’m sorry so far, apart from this one, I only had time to read your posts on Capital I Chapter 1 – Parts 1 and 2.
https://boffyblog.blogspot.co.uk/2012/07/capital-chapter-1-part-2.html

There in those posts money does not as yet exist. So it’s easier and simpler for us here to keep money out of the equation too (till later).

Then we can also keep skilled labour out of the equation (when it does not add to clarity) like this:

“… But how does one measure quantities of labour? By the time the labour lasts, in measuring the labour by the hour, the day, etc. Of course, to apply this measure, all sorts of labour are reduced to average or simple labour as their unit…”
(Marx)

We can also think of all commodities exchanging neither above nor below but exactly at their values (till later).

Of course to trace the beginnings of money is not to assume that money already exists. Once we keep money completely out of the equation we cannot say:

Commodity “a” is worth so much money

But we can still say:

Commodity “a” is worth so much of commodity “b”.

Or:

10 grams of gold is worth a kilo of yarn.
A kilo of yarn is worth 10 grams of gold.

A kilo of yarn is worth 10 grams of gold.

That way around the yarn acts as the relative for the gold and the gold acts as the equivalent for the yarn.

Gold needs to be a use-value different to yarn to act as its equivalent – to act somehow as something of some one same social quality as the yarn. It shares only one same social quality with the cloth and that is labour not spinning or mining labour but labour in the abstract.

In “a kilo of yarn is worth 10 grams of gold” the yarn stands out as relative value. The yarn says that it has value by saying that the equivalent is exchangeable for it.

The use-value of gold is acting as its opposite – the value of the yarn.

The Concrete labour that produced use-value (gold) stands for its opposite – that is it stands for the Abstract labour that produced the value of the yarn.

Private labour (miner’s labour) stands for its opposite – social labour (the social labour that is the value of the yarn).

A commodity already has use-value and value, before its owner has brought it to market – even though its exchange-value is meanwhile hiding out of sight so we can’t see it. Exchange-value is therefore a result and not a cause, of value.

In:

“A kilo of yarn is worth 10 grams of gold”

The use-value yarn acts as (stands for) use-value.

The use-value gold acts as value – as the mirror it shows up the value of the yarn because acting as equivalent – exchangeable for the yarn.

Boffy said...

Thanks for your further comments. I am busy at the moment, and unable to reply to both comments. Just to reply to the first one, therefore, what Marx says in the quote you gave is exactly what I said. When power looms were introduced, the hand loom workers continued to work the same number of hours, as before. They continued to create the same amount of value as before, embodied within the individual value of their output.

But, commodities do not sell according to their individual value, but according to their "social" value, i.e. not according to the amount of labour actually embodied within them, but according to the quantity of socially necessary labour required for their reproduction. If you read my posts on individual value, and Marx's analysis in Capital Volume III, where he discusses the determination of this social value, or market value in conditions where the market is dominated by capitals that produce below at or above the average level of efficiency, i.e. where they embody more, the same or less than the average socially necessary labour, this becomes clear.

I'll reply to your other comments when I have time.

Unknown said...

That’s fine,

Now I do see.

Marx was speaking apart from those modifications which you mean:

“… apart from the effect of monopolies and some other modifications I must now pass by…”
(Marx)

To begin with we can also speak apart from those modifications (till later).

Boffy said...

Thank you for your further comment. I am glad that you now understand the point that was being made in that regard. I can now reply briefly to the second comment, which I had yesterday not had time to cover. Unfortunately, I have to split it into two because of the character limit.

You say,

“Why do consumers value the product of one type of labour compared to another? What changes their minds?”

There is implied here, and contained in your further comments, the confusion I was referring to in a previous reply, in the way you deal with use value and value. You are interpreting “product of labour” here, as some concrete product, for example a metre of linen, or a gram of gold. In other words, you are interpreting “product of labour” here as meaning the resultant use value, linen or gold, and then comparing the value represented by one of these use values relative to the other. Incidentally, to save you time setting out these relations, you can simply refer to the value form, relative form of value, or equivalent form of value, definitions for all of which I have set out in the Glossary of Marxist terms.

But, when I speak here of “product of labour”, I am using the term in the way Marx discusses in this context to mean not the use value produced, but the value produced by these differing forms of concrete labour in a given specific period of time, i.e. the value product of the labour. So, we know, for example, that setting aside the value of the material used, it was common practice for peasants to work on the land of a blacksmith, for the same amount of time that the blacksmith was shoeing the peasants horse. In other words, what we are talking about here is direct exchanges of amounts of living labour. But, the peasant may value the labour of the blacksmith more highly than their own, and so might be prepared to spend 2 hours working on the blacksmith's land for every hour the blacksmith spends shoeing their horse.

We do not know why consumers value one type of labour more than another, is the simple answer. Bourgeois economics has spent literally billions of dollars trying to uncover the psychological determinants of consumer preferences largely without success. Why do consumers value the labour of a footballer, a film star, or some other entertainer more highly than that of a nurse, or a brain surgeon? Answers on a postcard! And, that is precisely the point that Marx makes. It not determinable a priori, but only a posteriori, in the market when we see the results of the actual exchanges.

When you say,

“But I just said that the hand-loom weaver adds value to his means of production…”

That is the correct interpretation and the point I was making. How much value does the weaver add by an hour of their labour, and how much value does a gold producer add by an hour of their labour? Now, Marx has identified gold as the money commodity, the universal equivalent form of value, and, he says, thereby has made gold mining labour the general form of labour, the proxy for abstract labour. The point then being that its quite clear that this gold mining labour, as a proxy for abstract labour, is not at all the same thing as simple labour. Simple labour is base 1, so that every other form of non-simple labour, i.e. complex labour, represents some multiple of it.

(Cont'd)

Boffy said...

Cont'd.

An hour of a gold producer, to use your correct formulation, adds (by definition, because it is the proxy for abstract labour) one hour of value to his means of production. Now to again use your correct formulation, the weaver may add two hours of value to his means of production, by expending one hour of his labour. In that case, if these were the only types of concrete labour, the gold miner's labour would be simple labour, and the weaver's labour complex labour producing double the new value of that of the gold producer. But, there is no reason this has to be the case. It could be that the weaver only adds the equivalent of half an hour of new value by the expenditure of their labour. In which case, either we have to continue to classify the gold producer's labour as not only abstract labour, but also simple labour, and thereby to determine the weaver's labour as something less than simple labour, as merely a fraction of simple labour, or inversely complex, or else we have to set the weaver's labour as base 1, as simple labour, so that then the gold producer's labour, the proxy for abstract labour, represents complex labour in relation to it.

You then give this quote from Marx, which illustrates the problem.

“… But how does one measure quantities of labour? By the time the labour lasts, in measuring the labour by the hour, the day, etc. Of course, to apply this measure, all sorts of labour are reduced to average or simple labour as their unit…”

But, which is that it is reduced to the average or the simple? If its reduced to the simple, and the simple is base 1, then it clearly cannot be the average, unless all labour is homogeneous, in which case the problem would not exist at all! If it is the average, then likewise it cannot be reduced to the simple. If we have 3 types of labour, A,B and C, and in an hour they produce 1,2 and 3 hours of value respectively, (which we might determine relatively by how much each exchanges for a fourth type of labour X) then B represents the average, and it is complex labour in relation to the first, but inversely complex in relation to the third. If we choose, the first one, which produces the least value in an hour, and thereby represents base 1, we can then see that the second and third types of labour are both complex in relation to it, but it is not at all the average labour.

The further discussion provided in your comment, as I said at the beginning is not relevant, because it confuses “product of labour”, meaning the value product of each type of labour created in a given period of time, with the use value produced by that labour in a given period of time. The issue here is not the exchange value of commodities whether considered in terms of the relative form of value, equivalent form of value, or their price, i.e. the universal equivalent form of their value, but is the new value created by each type of labour during a given period of time.

Unknown said...

So to begin with we take value in its purity without disturbing vibrations which are not helpful here. Or they are helpful only in that they cause all commodities to exchange on average at their values. Later modifications are for later.

Here is a key sentence:

“… If its reduced to the simple, and the simple is base 1, then it clearly cannot be the average, unless all labour is homogeneous, in which case the problem would not exist at all!”
(Boffy)

So now the problem does not exist at all.

In:

Commodity “a” is worth commodity “b”
Commodity “b” is worth commodity “a”

After competition has now taken effect “a” is worth “b”... because each has just one social quality the same. That is labour which is all the same stuff or homogeneous. The proof is that we speak in terms of quantities. We say that 1 of “a” is worth 1 of “b”.

It follows that there has to be some identical quality both in “a” and in “b”.

That identical quality can come in units of the hour, the day, etc. it follows that it is of the same stuff.

The proof is that it answers the question.

Further proof is that there is no other answer.

Like all truer answers it changes everything.

For further proof take for instance the question of skilled labour.

Skilled labour adds to means of production 2, 3, 4 etc. x more than does unskilled labour in equal times. We only learn it from how products exchange in the market.

But why does the product of an hour of skilled labour count for more?

I mean: “… apart from the effect of monopolies and some other modifications I must now pass by…”
(Marx)

The only answer possible is that society needs to put more labour on the average into producing the commodity skilled labour-power.

That the product of an hour, day, etc. of skilled labour counts as 2, 3, 4 etc x more than that of unskilled labour is the result.

Then society – the market competition – reduces 1 hour of skilled labour to 4 hours of unskilled. Then we are dealing in units of the same stuff – abstract labour.

Boffy said...

You are confusing skilled and unskilled labour here with complex and simple labour. As Marx says, there is no reason that skilled labour must be complex, and unskilled labour simple. It depends how consumers of the different types of the concrete labour subjectively value them.

For example, is a brain surgeon more or less skilled than a football player, or a pop singer?

You then also confuse the value produced by labour and the value of labour-power. It may require much more social labour-time to produce the labour-power of a brain surgeon than it does the labour-power of a pop singer, but as Marx says clearly the value of labour-power in neither case determines the value produce by either type of labour.

Boffy said...

You say,

"So now the problem does not exist at all."

But, it only does not exist at all if all labour is homogeneous, as I stated. But all labour is NOT homogeneous, as Marx clearly states. If it was homogeneous he would not have the categories simple and complex!

Boffy said...

You also say,

"After competition has now taken effect “a” is worth “b”... because each has just one social quality the same. That is labour which is all the same stuff or homogeneous. The proof is that we speak in terms of quantities. We say that 1 of “a” is worth 1 of “b”."

But, we don't say that where the actual abstract labour contained in one commodity is different to that in the other, even where the amount of concrete labour is the same. You seem to have put yourself in a circular argument, where you have also made as an assumption that which you have to prove.

If the labour contained in commodity a is complex labour, and the labour contained in commodity b is simple labour, there is no reason why we should, and every reason why we should not say that 1a is worth 1b!

Unknown said...

You said:
“You are confusing skilled and unskilled labour here with complex and simple labour. As Marx says, there is no reason that skilled labour must be complex, and unskilled labour simple. It depends how consumers of the different types of the concrete labour subjectively value them.

”For example, is a brain surgeon more or less skilled than a football player, or a pop singer?

”You then also confuse the value produced by labour and the value of labour-power. It may require much more social labour-time to produce the labour-power of a brain surgeon than it does the labour-power of a pop singer, but as Marx says clearly the value of labour-power in neither case determines the value produce by either type of labour.”
(Boffy)

Your question: “… For example, is a brain surgeon more or less skilled than a football player, or a pop singer?”

Yes of course if society needs to spend more labour time on the average to produce his labour-power.

You add that I: “… confuse the value produced by labour and the value of labour-power…”

If society needs to spend all told x labour time on the average to produce a commodity then value of commodity is also x.

If society needs to spend on the average skilled labour to produce a commodity then skilled labour does add more value in the same time than unskilled.

But:

“… Let us now consider the residue of each of these products; it consists of the same unsubstantial reality in each, a mere congelation of homogeneous human labour, of labour-power expended without regard to the mode of its expenditure. All that these things now tell us is, that human labour-power has been expended in their production, that human labor is embodied in them. When looked at as crystals of this social substance, common to them all, they are—Values…”
(Marx)
http://www.econlib.org/library/YPDBooks/Marx/mrxCpA1.html#I.I.11

Homogeneous labour is a bit like homogenised milk. The cream is in there somewhere but all blended into the same stuff.

Boffy said...

"If society needs to spend on the average skilled labour to produce a commodity then skilled labour does add more value in the same time than unskilled."

This is fundamentally wrong, and demonstrates your confusion of labour with labour-power.

Let us suppose that we take a commodity yarn.

A spinner takes 10 kilos of cotton which have required 10 hours of labour-time to produce. He works for 20 hours turning this cotton into yarn. The yarn then has a value of 20 hours. However, the spinner actually only needs to work for 10 hours to reproduce the value of their labour-power. In that case, they produce a surplus value of 10 hours.

Now, if the labour of the spinner is more skilled labour, which requires more labour for its reproduction, what is the situation? Suppose the spinner's labour requires 15 hours of labour for its reproduction. In that case, we would have

cotton (c) - 10 hours
new value added by labour 20 hours. Now divided 15 hours wages/value of labour-power (v) 5 hours surplus value (s).

As Marx explains, it would be just the same as if, instead of the labour being used being more skilled and so the labour-power having a higher value, the level of social productivity was lower so that all labour-power required more labour-time for its production, so that the value of all labour-power was higher.

Boffy said...

Cont'd

What you have fallen into here is the same mistake as Adam Smith. Instead of a labour theory of value, you have presented a cost of production theory of value whereby the value of output rises or falls with the value of the labour-power used in its production. As marx sets out at length and in detail, that was a fundamental error of Adam Smith, and versions of it can be found also in Proudhon.

It is the very fact that the value of labour-power has no bearing upon the value created by labour, which makes possible not just surplus value, but indeed all social progress. It is the very fact that the value created by labour exceeds the value of the labour-power which makes a surplus value and a surplus product possible, so that accumulation of means of production/capital can occur so that productivity can rise, and increasing amounts of surplus product/value be created.

To go back to the example I previously gave, it may require much more labour-time to produce the labour of a brain surgeon than that of a pop star, but that tells us absolutely nothing about the value produced by these different concrete labours. It may require 10,000 hours to produce the labour-power of the brain surgeon, and only 2,000 hours to produce the labour-power of the pop star. However, the labour of the brain surgeon may create only 20,000 hours of new value, whereas the labour of the pop star may produce 100,000 hours of new value, or more.

What the actual metrics are, as Marx says can never be determined a priori, because it depends upon how consumers value these respective types of labour, which again has nothing to do with how much labour went into the production of those particular labour-powers. It is why we have TV programmes to find new pop stars, and so on, but why we do not have programmes to select the next top brain surgeon, i.e. although the latter's labour-power may have a higher value, the value their labour produces is only a fraction of that of a pop star, footballer, film star and so on.

I think I have probably gone as far as I can in explaining this to you without repeating myself, and besides this being all pretty basic stuff contained in Capital I, and in numerous of my other posts, I will be returning to it, in January in dealing with Marx's analysis in Theories of Surplus Value Part I, where he deals with the confusion you have presented here, in dealing with the same confusion of Adam Smith, whereby he Smith slips from a labour theory of value into a cost of production theory of value, which is also the basis of his "absurd dogma" that the value of commodities resolves into factor incomes, and whereby, therefore, he too comes to determine the value of commodities, and changes in their value, by changes in wages.

Boffy said...

Correction:

I said above,

"A spinner takes 10 kilos of cotton which have required 10 hours of labour-time to produce. He works for 20 hours turning this cotton into yarn. The yarn then has a value of 20 hours."

That should read, of course, "then has a value of 30 hours."

Unknown said...

Thank you yes I guessed that was just a typing error.

Please feel free to email me your draft on Theories of Surplus Value Part I to thedevilsatan1@gmail.com

I will share my take on it with you before you post it.

Millionaire surgeons or singers are spending their millions on stuff which took hours on hours of labour to produce but which the spender never needs to work. They are exploiting workers. We can discuss that but as I say later modifications are for later.

I am explaining the value of the total social product as the total labour in it rather than the total wages/value of labour-power.

And I still say:

“… All labour of a higher or more complicated character than average labour is expenditure of labour-power of a more costly kind, labour-power whose production has cost more time and labour, and which therefore has a higher value, than unskilled or simple labour-power. This power being of higher value, its consumption is labour of a higher class, labour that creates in equal times proportionally higher values than unskilled labour does…”

And that in no way stops surplus value:

“… Whatever difference in skill there may be between the labour of a spinner and that of a jeweller, the portion of his labour by which the jeweller merely replaces the value of his own labour-power, does not in any way differ in quality from the additional portion by which he creates surplus-value. In the making of jewellery, just as in spinning, the surplus-value results only from a quantitative excess of labour, from a lengthening-out of one and the same labour-process, in the one case, of the process of making jewels, in the other of the process of making yarn…”
(Marx)
http://www.econlib.org/library/YPDBooks/Marx/mrxCpA7.html#a18

Unknown said...

Sorry I meant to add this link also:
http://www.econlib.org/library/YPDBooks/Marx/mrxCpA7.html#III.VII.55

Boffy said...

As I said, I don't think I can really add anything to explain all of this to you without repeating what has already been said, and what might be added of substance I will be covering in January when I come to deal with Theories of Surplus Value, where Marx deals with the confused views of Adam Smith, which you have basically repeated here. So, this will be my last comment, as I have a lot of other things to do currently.

Marx's statements above merely make the point that the labour of any worker be they of a spinner or a jeweller is the same during that part of the day that they undertake necessary labour and that part when they undertake surplus labour. What you have done, as Smith does, which leads him to his cost of production theory of value as opposed to his labour theory of value is to reverse the arrow of causation.

The reason that a worker might obtain higher wages than the average, is because their labour produces a lot of value, i.e. it is complex rather than simple labour. It is not the other way around that the value of commodities is high. What is relevant here, is the point that Marx sets out in CapitaL III, in discussing the historical development of prices of production and the average rate of profit, concerning the assumption of a common rate of surplus value.

In other words, take some area of production where the labour produces a high level of value, i.e. it is complex labour. If the value of this labour-power is no greater than the average, i.e. it is normal unskilled labour, this labour would produce a large surplus value. As Marx sets out under petty commodity production, other commodity producers would seek to take part in such production themselves, so that the supply of that particular type of labour and commodity would rise, reducing its value, and restoring an average rate of surplus value.

But, if we take something such as a footballer. Their labour produces huge amounts of new value, and as the product of their labour can be consumed by ever larger audiences simultaneously the value produced by their labour rises, whilst the value of their labour-power does not. They produce large amounts of surplus value, which would go to the football club as a surplus profit, encouraging others to set up in that business. But, the supply of top class footballers is limited. Footballer's wages rise, as essentially a rent taken from the football club's surplus profits. But, it is not that footballer's have high wages, or a high value of their labour-power, which causes the value produced by their labour to be high, which is the view you have put forward here, and which was the error that Adam Smith fell into, as I will illustrate in my posts on TOSV next year.

Boffy said...

Correction.

It should read above,

"It is not the other way around that the value of commodities is high, because the value of labour-power used in their production is high."

Unknown said...

Ok so you mean:

“… The reason that a worker might obtain higher wages than the average, is because their labour produces a lot of value, i.e. it is complex rather than simple labour. ‘It is not the other way around that the value of commodities is high, because the value of labour-power used in their production is high...’”

I already rejected both ways round. I already rejected this arrow of causation –> as I rejected that arrow of causation <–

I am explaining the value of the total social product – all commodities – as the total labour in it rather than as the total wages/value of labour-power.

In this the commodity labour-power is no different. The value of labour-power is quite simply the labour that it takes on the average to maintain and produce it.

There’s plenty of time for what you have been discussing. I hope that you have mailed your drafts to me. But the top footballer (the top few) was not relevant here because society cannot produce him at will and in numbers. The next to top footballers or most footballers would have been relevant here because society can produce them at will and in numbers.

You say it’s how consumers value commodities.

You see that in equal working lifetime the brain worker who has high training and experience (you class him as skilled). He adds more value to the means of production than the manual worker who needs less training or experience. You class him as unskilled.

Next you see a complete change. Skilled changes places with unskilled. In equal working lifetime the manual worker, with low training, (you now class him as skilled). He adds more value to the means of production than the brain worker who has the training and experience.

But then you see yet another change. Skilled and unskilled change places once more. Once more you see that in equal working lifetime time the brain worker who has high training and experience (you now class him as skilled once more). He adds more value to the means of production than the manual worker who needs less training or experience. Once more you class him as unskilled.

How is it that you cannot explain these changes simply or in terms of common workers who society can produce at will and in numbers?

How is it that you cannot do so without needing the adjustments for the historical development of prices of production and the average rate of profit, concerning the assumption of a common rate of surplus value?

And how is it that you cannot do so before next year?

I shared the explanation with you.

Please see my links to Marx Capital above.

Unknown said...

I just want to thank you.

It’s only because you are busy that sadly you have only half-read what I said and Happy New Year

Unknown said...

While we wait for Boffy to have time to explain skilled-labour it is clear from the start that we should be ready to discuss any half likely arrows of causation –>

Our job here is just to find the fewest arrows of causation –> that explain a change.

To start with buyers must find commodities useful or they would not buy them. I accept that arrow of causation <– as starting point only. I reject it as more than starting point.

And it will never do to explain the values in exchange of commodities in this way:

Value of “a” is the result of value of “b” and value of “b” is the result of value of “a”.

That is empty argument in a circle.

In exactly the same way it will never do to explain the value of the commodity “a” by the value of the commodity labour power/wages.

I reject that arrow of causation –> in that we need an explanation of the value of All commodities.

The explanation for the value of all commodities will include the explanation for the value of the commodity labour power/wages.

If it costs society labour time to produce food clothes shelter training… then it also costs society labour time to produce the commodity labour power because there’s no labour power without food clothes shelter training…

If society needs to spend all told x labour time on the average to produce a commodity then value of commodity is also x.

If society needs to spend on the average skilled labour to produce a commodity then skilled labour does add more value in the same time than unskilled.

That statement is wrong.

So says Boffy.

Listen to Boffy:

“… This is fundamentally wrong, and demonstrates your confusion of labour with labour-power…”
(Boffy)

But if skilled labour adds no more at all in the same time then what exactly does Boffy mean by skilled labour?

If Boffy is correct and skilled labour adds no more value than unskilled then these next words are also fundamentally wrong:

If society needs to spend on the average just unskilled labour to produce a commodity then unskilled labour adds less value in the same time than skilled labour does.

So according to Boffy’s claim these next words are correct:

If society needs to spend on the average skilled labour to produce a commodity then skilled labour adds an identical amount of value in the same time as unskilled.

But if skilled and unskilled are identical then the problem of their variability does not exist at all.

If Boffy is correct and skilled labour is just like unskilled? And if unskilled labour is just like skilled? Then why is his post here? Why the need to mention abstract labour? Why is his post about the difference between skilled and unskilled labour? Does Boffy mean that his whole post is fundamentally wrong?

Unknown said...

Let’s attack the difficulty another way.

Just for a change let’s think of Crusoe all alone on his island.

Crusoe needed to spend an hour today towards building a boat plus an hour of clearing leftover trash for firewood.

So with finger in sand Crusoe is writing how he worked 1 hour boatbuilding and 1 hour clearing trash for firewood = 2 hours.

Crusoe’s boatbuilding skill cost him a lot of learning. But Crusoe’s trash clearing know-how cost him hardly any learning.

In his bookkeeping does Crusoe count 1 hour of boatbuilding labour as worth the same as trash clearing?

Yes.

Whatever Crusoe does to stay alive, boatbuilding or trash clearing, is the labour of Crusoe. He can measure his labour in time by his wind-up watch. In this way he learns in practice how many hours on the average that all his products are costing him.

Any devils who are curious about the future alternative to our market economy can learn much from Crusoe. That’s because Crusoe’s island is the future alternative to our market economy – but smaller. I mean the free worker’s co-op of the future is Crusoe’s island – but bigger.

Of course Crusoe could count 1 hour of his skilled labour as worth 2, 3 or 4 hours of his unskilled.

Then we get:

An hour boatbuilding (I hour skilled = 2 hours of unskilled) plus an hour clearing leftover trash for firewood = 3 hours.

In this way Crusoe has just classed every hour of his skilled labour as now worth 2 hours of his unskilled. 1 hour of unskilled is his basic unit and an hour of skilled now counts as 2 of those units.

But normally Crusoe just counts 1 hour of skilled labour as equal to 1 hour unskilled.

Our question is:

What happens in our market economy where the private producer has no business with all the other private producers until all sell their products in the market?

With us one worker is skilled boat builder all of the time. But the next worker is trash clearer all of the time.

With us Boffy cannot do what Crusoe can do and rule that it’s fundamentally wrong for the skilled labour to add in equal time more value to the boat than unskilled.

With us it is rather for the market to rule on the exact identity or difference between skilled and unskilled.

With us it is for the market competition which behind our backs says that 1 hour of skilled labour for the present will count as 2, 3 or more hours of unskilled. It is in this way that the market competition reduces all labour to units of the same kind. And that is a unit of unskilled labour. 2 or more hours of unskilled = 1 hour of skilled. We cannot know and nor do we need to know the exact ratio.

What I have said is enough to bring us to this question:

With us what is it that changes unskilled labour into skilled labour?

If you look up the page Crusoe has already answered this question.

And if you look still further up the page so has Marx.

Of skilled Marx says:

“…All labour of a higher or more complicated character than average labour is expenditure of labour-power of a more costly kind, labour-power whose production has cost more time and labour, and which therefore has a higher value, than unskilled or simple labour-power. This power being of higher value…”

And:

“…This power being of higher value, its consumption is labour of a higher class, labour that creates in equal times proportionally higher values than unskilled labour does…”
(Marx)

I’m here defending the answers of Crusoe and Marx.

That’s not because it’s Crusoe and Marx.

It’s rather that so far I see no rival answer here which stands up to the facts.

Here once more are the links to Marx Capital:

http://www.econlib.org/library/YPDBooks/Marx/mrxCpA7.html#III.VII.55

http://www.econlib.org/library/YPDBooks/Marx/mrxCpA7.html#a18

Unknown said...

Sometimes it happens that the simple explanation is also the right explanation:

“… The distinction between skilled and unskilled labour rests in part on pure illusion, or, to say the least, on distinctions that have long since ceased to be real, and that survive only by virtue of a traditional convention; in part on the helpless condition of some groups of the working-class, a condition that prevents them from exacting equally with the rest the value of their labour-power. Accidental circumstances here play so great a part, that these two forms of labour sometimes change places. Where, for instance, the physique of the working-class has deteriorated, and is, relatively speaking, exhausted, which is the case in all countries with a well developed capitalist production, the lower forms of labour which demand great expenditure of muscle, are in general considered as skilled, compared with much more delicate forms of labour; the latter sink down to the level of unskilled labour. Take as an example the labour of a bricklayer, which in England occupies a much higher level than that of a damask-weaver. Again, although the labour of a fustian cutter demands great bodily exertion, and is at the same time unhealthy, yet it counts only as unskilled labour. And then, we must not forget, that the so-called skilled labour does not occupy a large space in the field of national labour…”
(Marx)
http://www.econlib.org/library/YPDBooks/Marx/mrxCpA7.html#a18

Obviously the real explanation of skilled labour must also explain those trends. Helpless groups of the working-class grow accustomed to living and learning their high skills while not eating enough food. In this way the value of their skilled labour-power sinks low.

At the same time certain less skilled trades could never physically do their heavy work – not if half-fed like the poor starving skilled workers. That’s why it’s not physically possible to lower the value of their labour-power so far that they are starving like the poor exhausted skilled workers.

That’s how it even happens that skilled and un-skilled can switch places. What was skilled changes into unskilled and vice-versa.

What we have here is a straight forward change in the amount of labour that society needs to produce one kind of labour-power compared to another.

Alternative explanations are really results: The difference in wage is a result. That what has become skilled labour is adding more value in the same time is a result. That the buyer (employer) thinks that what is now skilled labourer is worth more is a result etc.

What happens next?

As generations of workers learn in practice to fight back and to organise themselves they raise the value of their labour-power so the average worker is physically fit and can easily learn to do heavy work.

Then it’s the other kind of labour-power that calls for more learning which costs society more labour time to produce it. That’s the reason why we see the changing results or trends.

There’s no other explanation.