It seems absurd that one has to answer this question.

It was so thoroughly answered by previous generations of economists in the affirmative[12], that it would seem unnecessary even to examine the issue. But David Harvey has recently posted a short article[6] claiming that Marx was an opponent of the labour theory

It is widely believed that Marx adapted the labour theory of value from Ricardo as a founding concept for his studies of capital accumulation.  Since the labour theory of value has been generally discredited, it is then often authoritatively stated that Marx s theories are worthless. But nowhere, in fact, did Marx declare his allegiance to the labour theory of value.  That theory belonged to Ricardo, who recognized that it was deeply problematic even as he insisted that the question of value was critical to the study of political economy.  On the few occasions where Marx comments directly on this matter,1 he refers to value theory and not to the labour theory of value.  So what, then, was Marx s distinctive value theory and how does it differ from the labour theory of value?( [6])

It is difficult to take this seriously but as Mike Roberts has done a reply, I probably should do likewise and type a brief response.

Harvey claims that the labour theory of value is generally discredited. But in what sense?

It is correct to say that the theory is not viewed with favour in economics departments, but that is for political reasons – the labour theory of value came, since Gray and Marx, came to be associated with socialism. Since academic economists, in general, did not want to be tainted with the socialist label they were at pains to distance themselves from the theory. But none of them ever adduced any empirical evidence to refute it. It was socially discredited but not empirically refuted.

If one wants to refute a theory about the world you have to show that the theory makes incorrect empirical predictions. Eratosthenes refuted the theory that the Earth was flat and confirmed the theory that it is round by observing that when the sun was overhead in Syene it was at an angle of 7°12′ to the vertical in Alexandria, implying that the earth was curved with a circumference of 25,000 miles. If the earth had been flat the angle of the sun would not have varied as you went north.

The labour theory of value predicts that the prices of commodities will vary proportionately with their labour content. Refuting this should be easy, just show that in fact their prices do not vary with labour content in this way. Did the economists opposed to the labour theory of value do this?

Did they hell, they did not even bother to collect the data to do the tests. So for a century after Marx, the theory was ‘discredited’, but never empirically refuted.

As soon as economists started to collect data to test the theory, which depended on reasonably good economic statistics of whole economies, what did they find?

They found the Ricardo and Marx had been right all along. A whole bunch of studies[18,17,5,13,15,19,1,4,2] since the 1980s have shown that the labour theory of value is very good at predicting prices. Far from being refuted by the evidence, it has been confirmed.

Harvey is like a flat-earther after Erastosthenes, denying the Earth is round on theological grounds.

Harvey next complains that Marx nowhere declares his allegiance to the labour theory of value. True enough, since at the time Marx was writing, that was the only theory going. It simply was the theory of value. It was only afterwards that the alternative marginal utility or neo-classical theory of value was established. After Jevons[8] economists distinguished between the classical or labour theory of value and the neoclassical or marginalist theory of value. But it is ridiculous to expect Marx to have taken sides in a debate that only started after Capital was published(1867). At the time he was writing it was widely accepted that labour was the source of value. Even Jevons the founder of marginalism still accepted that prices were proportional to labour1, thinking that his marginal utility theory gave further support to this time honoured assumption.

Harvey promises to explain what Marx’s theory of value actually is, but nowhere in his article does he do this. That is because it would be impossible to do this without revealing that the theory of value in Marx is identical in all major predictions to that of Ricardo.

What did Ricardo’s theory say?

Did Marx agree with him?

When comparing theorists, especially ones who originally wrote in distinct languages, you should not pay too much attention to the precise vocabulary that they use. What is important is the relations between the concepts they deploy and the relationships that the theorists predict will hold in the real world. When you look at this you see that Marx followed Ricardo’s value theory very closely.

There are 4 key components to their value theory on which both authors agree:

  1. The exchangeable value of commodities varies with their direct labour content2,3.
  2. The indirect labour used to make raw materials and equipment also contribute proportionately to the exchange value4,5.
  3. It is the labour actually expended not the level of pay of the workers that determines value6,7.
  4. The variation of price with labour will be modified by the formation of an equal rate of profit on stock.8,9

The theories are therefore substantially identical in the empirical predictions they make, differing only slightly in terminology. Points 1,2,3 are validated by the empirical data in the studies cited earlier. Point 4 is poorly supported by or refuted by the empirical data [5,19,3] . Marx and Ricardo say the same thing where they are both right and say the same thing where they are both wrong.

So yes Marx has a labour theory of value as Ricardo had. The greater part of this theory is not refuted by the evidence, it is confirmed by it.

This does not mean that Marx made no contributions. Major innovations in his thought were:

  • The point that labour only gets represented as exchange value in societies with private ownership and atomised production. Marx says exchange was absent in traditional Indian communities or the communism of the Incas. The prior economists had assumed that all societies produce commodities.
  • The distinction between labour and labour power.
  • The introduction of the concept of surplus value as something functionally prior to the division of surplus value between profit, interest and rent.
  • A new theory to explain the falling rate of profit.
  • A repudiation of Say’s law.
  • The concept of absolute ground rent.
  • The introduction of more modes of production than the ones Adam Smith recognised.
  • The idea that the class struggle leads to the dictatorship of the proletariat.

These are all significant innovations that did distinguish him from his predecessors. There is no need to pretend innovation by Marx in value theory, a topic where he just rigorously used Ricardo’s concepts.

But what about abstract/concrete labour?

Was this distinction not an innovation on Marx’s part?

Well the specific phrase ‘concrete labour’ was different, but the relevant conceptual distinction between the two was present in Adam Smith’s work.

Smith simply uses the term ‘labour’ unqualified where Marx sometimes says abstract labour10. Smith specifically says that when he is talking of labour in this way he is talking of labour in the abstract11. When Smith discusses the division of labour, he is discussing the division of the abstract labour into what he terms ‘varieties’ of labour12 or ‘sorts’ of labour13. This is the same distinction that Marx is making when, using the slightly different term, he talks of abstracting from concrete labours or kinds of labour14.

In tabular form we have:

Smith Marx
variety, kind, palpable kind, concrete
labour, abstract abstract-labour

The same conceptual distinction is being made here between the different kinds of activities into which the labour is divided, and labour in the abstract, or the abstract notion of labour.


W Paul Cockshott, A Cottrell, and GJ Michaelson. Testing Labour Value Theory with input/output tables. Department of Computer Science, University of Strathclyde, 1993.

W Paul Cockshott and Allin Cottrell. The scientific status of the labour theory of value. IWGVT conference at the Eastern Economic Association meeting, in April, 1997.

W Paul Cockshott and Allin Cottrell. Does marx need to transform. Marxian economics: A reappraisal, 2:70-85, 1998.

W Paul Cockshott and Allin F Cottrell. Labour time versus alternative value bases: a research note. Cambridge Journal of Economics, 21(4):545-549, 1997.

Nils Fröhlich. Labour values, prices of production and the missing equalisation tendency of profit rates: evidence from the german economy. Cambridge journal of economics, 37(5):1107-1126, 2013.

David Harvey. Marx’s refusal of the labour theory of value, 2018.

William S. Jevons. Theory of Political Economy. Sentry Press, 1871.

William Stanley Jevons. Brief account of a general mathematical theory of political economy, by william stanley jevons journal of the royal statistical society, london, xxix (june 1866), pp. 282-87.Journal of the Royal Statistical Society, 29:282-87, 1866.

Karl Marx. Value, price, and profit. CH Kerr & Company, 1910.

Karl Marx. Capital, volume 1. Progress Publishers, Moscow, 1954. Original English edition published in 1887.

Karl Marx. Capital, volume 3. Progress Publishers, Moscow, 1971.

Ronald L Meek. Studies in the labor theory of value, volume 428. NYU Press, 1956.

P. Petrovic. The deviation of production prices from labour values: some methodolog and empirical evidence. Cambridge Journal of Economics, 11:197-210, 1987.

David Ricardo. Principles of Political Economy and Taxation. In P. Sraffa, editor, The Works and Correspondence of David Ricardo, volume 1. Cambridge, 1951.

A. M. Shaikh. The empirical strength of the labour theory of value. In R. Bellofiore, editor, Marxian Economics: A Reappraisal, volume 2, pages 225-251. Macmillan, 1998.

Adam Smith. The Wealth of Nations. 1974.

Lefteris Tsoulfidis and Dimitris Paitaridis. Monetary expressions of labor time and market prices: Theory and evidence from china, japan and korea. Review of Political Economy, 2016.

David Zachariah. Testing the labor theory of value in Sweden., 2004.

David Zachariah. Labour Value and Equalisation of Profit Rates. Indian Development Review, 4(1):1-21, 2006.



“thus we have proved that commodities will exchange in any market in the ratio of the quantities produced by the same quantity of labour.” ([7]page 187)

2“If the quantity of labour realized in commodities, regulate their exchangeable value, every increase of the quantity of labour must augment the value of that commodity on which it is exercised, as every diminution must lower it.” [14]Chap. 1 , Sec. 1


4“Not only the labour applied immediately to commodities affect their value, but the labour also which is bestowed on the implements, tools, and buildings, with which much labour is assisted”[14]Chap. 1 Sec. 2


6See Ricardo’s criticism of Adam Smith for confusing the labour content of commodities for the labour that a commodity will exchange against.

7The whole argument of [9] is devoted to showing that trades unions can raise wages and raise the wage share and that such rises in wages will not simply result in higher prices.

8[14]Chap. 1, Sec. 4

9[11] Part II




“The greater part of people, too, understand what is means by a quantity of a particular commodity, than by a quantity of labour. The one is a plain palpable object; the other an abstract notion, which though it can be made sufficiently intelligible, is not altogether so natural and obvious.” ([16], page 23 Kindle edition)


“What a variety of labour, too, is necessary in order to produce the tools of the meanest of theose workmen! To say nothing of such compicated machines as the ship of the sailr, the mill of the fuller, or even the loom of the weaver, let us consider only what a variety of labour is requisite in order to form tat very simple machine, the shears with which the shepherd clips the wool. The miner, the builder of the furnace for smelting the ore, the feller of the timber, the burner of the charcoal to be made use of in the smelting-house, the brickmaker, the bricklayer, the workmen who attend the furnace, the millwright, the forger the smith, must all of them join their different arts in order to produce them.” .([16], page 12-13 Kindle edition)


“The spinner is almost always a distinct person from the weaver; but the ploughman, the harrower, the sower of the seed, and the reaper of the corn, are often the same. The occasions for those different sorts of labour returning with the different seasons of the year, it is impossible that one man should be constantly employed in any one of them. This impossibility of making so complet and entire a separation of all the different branches of labour employed in agriculture, is perhaps the reason why the improvement of the productive powers of labour, in this art, does not always keep pace with their improvement in manufactures.”[16], page 9-10 Kindle edition)


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