Precursors to Adam Smith While the labor theory of value is most closely associated with the classical economists, its intellectual antecedents can be traced to earlier economic thought. These early theories reflected the prevailing economic systems and evolved as commodity production became more widespread.
Canonist and Mercantilist approaches Early
Canonist writers, such as
Thomas Aquinas, were concerned with the ethical problem of the "
just price" in a society of small independent producers. They generally approached value from the perspective of the producer. The just price was seen as being based on the producer's costs, which included labor expended, risk, and transport costs. The goal was to ensure a price that was ethically just to both seller and buyer, with remuneration proportionate to outlay and effort. This focus on the "common good" of a hierarchical social order gave way to a new paradigm with the rise of commerce and the
Protestant Reformation. Thinkers like
John Calvin provided a religious rationale for the accumulation of capital, linking economic success to divine grace and shifting the focus from communal ethics to individual responsibility. With the expansion of commerce, the
Mercantilist school shifted the focus from production to exchange. Mercantilist writers tended to identify a commodity's value with its market price, which they saw as determined by the forces of
supply and demand. Writers like
Nicholas Barbon in his
A Discourse of Trade (1690) articulated this view, stating that "The Price of Wares is the present Value... The Market is the best Judge of Value". Barbon also emphasized utility as the source of value: "The Value of all Wares arise from their Use; Things of no Use, have no Value". This perspective reflected the concerns of merchants, whose profits were largely dependent on market fluctuations and "profit upon alienation"—buying cheap and selling dear.
Transition to classical value theory In the late 17th and early 18th centuries, particularly in Britain, the producer's cost approach to value was revived. This shift mirrored the rise of industrial capitalism and a growing concern with production costs. Writers began to analyze the relationship between market price and production costs, laying the groundwork for the classical concept of "natural price". This period saw the gradual recognition of
profit on capital as a general category of class income, distinct from interest on money or rent of land. Profit came to be seen not as originating in exchange ("profit upon alienation") but as an income associated with the use of capital in the employment of wage-labor.
William Petty was a key transitional figure who came remarkably close to the idea that exchange value is determined by the labor time required for production. In a well-known passage, he stated: "If a man can bring to London an ounce of Silver out of the Earth in Peru, in the same time that he can produce a bushel of Corn, then one is the natural price of the other". Thinkers like
John Locke argued that labor "puts the difference of value on everything," although his analysis primarily concerned labor's role in creating use value rather than exchange value. The concept of social labor as the determinant of value grew alongside the idea of the social
division of labor, with writers like
Bernard Mandeville and
Benjamin Franklin arguing that commerce was essentially an exchange of labor for labor. The author of an anonymous 1738 pamphlet,
Some Thoughts on the Interest of Money in General, provided a clear statement anticipating Smith: in early societies, the only rule for exchange was "the Quantity of Labour severally imployed in producing them".
Adam Smith Adam Smith, in
The Wealth of Nations (1776), developed the labor theory of value more systematically than his predecessors. His analysis, however, contains a tension between two different, and often contradictory, concepts of how labor determines value. His approach stemmed from his analysis of the division of labor in a "commercial society," where "every man thus lives by exchanging, or becomes in some measure a merchant." Smith's economic theory was an extension of his moral philosophy, articulated in
The Theory of Moral Sentiments (1759), in which the "
invisible hand" of the market acts as the objective mechanism that reconciles individual self-interest with the social good.
"Labor commanded" as the real measure of value Smith's primary theory posits that the value of a commodity is measured by the quantity of labor it can
command in exchange. He wrote: "The value of any commodity, therefore, to the person who possesses it...is equal to the quantity of labour which it enables him to purchase or command. Labour, therefore, is the real measure of the exchangeable value of all commodities." For Smith, labor was an invariable measure because the "toil and trouble" a laborer must sacrifice to earn his wages remains constant. Smith's purpose in distinguishing this "real price" from the "nominal price" (in money) was to create a measure for comparing the value of commodities over long periods. While the quantity of goods a given amount of labor can buy may vary, the value of the labor itself, from the perspective of the laborer, does not. This "labor commanded" concept was intended as a universal measure of value applicable to all societies. However, much confusion arose from Smith's "switching his subject" from the perspective of the laborer acquiring a commodity to that of the commodity owner commanding the labor of others. For the commodity owner, the value of labor is not constant, which undermines the raison d'être of the measure.
"Labor embodied" as the regulator of value Smith also proposed a second theory, stating that the value of a commodity is
regulated by the quantity of labor
embodied in its production. However, he argued that this principle only applies in "that early and rude state of society which precedes both the accumulation of stock and the appropriation of land." In such a society of independent producers, where the "whole produce of labour belongs to the labourer," the quantity of embodied labor would tend to equal the quantity of commandable labor. In a more advanced capitalist society, Smith argued, the "natural price" of a commodity must also cover profit on capital and rent of land. Therefore, the price no longer corresponds solely to the labor embodied in the commodity. The commodity's price resolves into three components—wages, profit, and rent—which Smith called "the three original sources ... of all exchangeable value." This became known as his "adding-up" or
cost-of-production theory of value, which stands in contradiction to his labor-embodied theory. Some scholars suggest that Smith's apparent contradictions can be understood through his "representational framework," in which value and its component parts (wages, profit, rent) are seen as mutually determining each other simultaneously, like mirror images, rather than one being the unidirectional cause of the other.
David Ricardo David Ricardo, in his
On the Principles of Political Economy and Taxation (1817), sought to resolve the inconsistencies in Smith's theory. Ricardo firmly established the quantity of embodied labor as the foundation of exchange value in all stages of society, not just in a primitive one. He stated unequivocally: Ricardo criticized Smith's "labor commanded" measure, arguing that it was no more invariable than the commodities it was supposed to measure. The value of labor itself, he contended, varies with the price of food and other necessaries. Unlike Smith, who tended to view capitalism as a "natural" order, Ricardo's analysis revealed the inherent class antagonisms of the system, particularly the inverse relationship between wages and profit.
Modifications to the theory Ricardo recognized that his principle was not absolute and required "considerable modification." His primary focus became the search for the causes of
changes in relative value. The main problem he grappled with was the effect of capital on relative prices. He demonstrated that a rise in wages would not cause all prices to rise, as Smith had thought. Instead, it would alter the relative prices of commodities produced with different proportions of fixed and circulating capital, or with capitals of different durability. For example, a rise in wages would lower the price of a commodity produced with a high proportion of durable machinery relative to a commodity produced mainly with direct labor. This was because the rise in wages would cause a fall in the general rate of profit, which would have a greater impact on the price of the more capital-intensive good. This issue, which exposed a contradiction between an embodied-labor theory of value and a cost-summation account of price, later became known as the
transformation problem. In his later work, Ricardo became increasingly concerned with finding an "invariable measure of value" to distinguish changes in a commodity's value caused by changes in its own production process from those caused by changes in the production of the money commodity. This search led him to develop the concept of "absolute value," which he tended to identify with the quantity of embodied labor. He viewed the effect of distribution changes (i.e., a rise in wages and fall in profit) on relative prices not as a separate "real" cause of value, but as an "apparent" cause resulting from the lack of a perfect, invariable measure. For Ricardo, the labor theory of value was ultimately not as central to his system as it would later be for Marx.
Karl Marx Karl Marx adopted and radically developed the labor theory of value, making it the cornerstone of his
critique of political economy. For Marx, the LTV was not merely a theory of relative prices but a tool to uncover the social relations of production underlying the capitalist economy. His purpose was to expose the "hidden nexus" that exists between individual producers and to discover the "economic law of motion" of the capitalist mode of production. He argued that "the mode of exchange of products depends upon the mode of exchange of the productive forces," and the labor theory of value was the key to understanding how this occurred. While his analysis of capitalist dynamics was primarily functional, his value theory was essentialist, seeking to uncover the "inner essence" of price relations. Unlike the classical economists who treated capitalist relations as natural and eternal, Marx, influenced by precursors like
Richard Jones, emphasized the historically specific character of economic categories like value, money, and capital. Marx did not see his work as a continuation of classical political economy, but as a critique of it. He criticized Ricardo, for instance, for positing an undifferentiated, transhistorical concept of labor and failing to examine the historically specific
form of labor that creates value.
Value, abstract labor, and fetishism In the first chapter of
Capital (1867), Marx begins his analysis with the commodity, which he identifies as the "simplest social form in which the product of labour presents itself in contemporary society". He makes a crucial distinction between "
use value", the utility of a commodity, and "
exchange value", the proportion in which it exchanges for other commodities. Contrary to some interpretations that Marx's analysis begins with a hypothetical pre-capitalist society of "
simple commodity producers," others argue that his analysis presupposes the capitalist mode of production from the very first sentence of
Capital. He argues that for commodities to be exchangeable, they must possess a common substance. This substance cannot be any physical property, since that relates to use value. By abstracting from their use values, the only property commodities have in common is that they are products of labor. This is not the concrete, useful labor that creates specific use values (e.g., tailoring, weaving), but
abstract labor—undifferentiated human labor in general, which is the substance of value. The "equalisation of all types of labour through market equalisation of all the products of labour as values," argued the Marxist economist
Isaak Illich Rubin, is what Marx meant by abstract labor; it is a "social and historical concept," not a physiological one. In this view, abstract labor is not just a mental generalization but a real social practice that acts as a unique form of social mediation in capitalist society, replacing the direct social relations (of kinship, dominance, etc.) that characterize other societies. The magnitude of this value is determined by the "
socially necessary labor time", the average time required for production. Marx also makes a crucial distinction, often overlooked, between
value and
material wealth. Value is a historically specific form of social wealth unique to capitalism, measured by labor time. Material wealth (use values) is transhistorical and its creation becomes increasingly dependent on science and technology, not just direct labor time. This growing divergence between value and material wealth is central to Marx's analysis of capitalism's inherent contradictions. Because value appears only in the exchange of products, the underlying social relations between producers are disguised. Labor appears not as a direct social relation between individuals but as a "material relation between persons and a social relation between things." Marx called this phenomenon the "
fetishism of commodities", where the economic categories of bourgeois society seem to be natural properties of things rather than expressions of a specific, historical mode of production. According to some interpretations, this means that the abstract social structures of capitalism (like value and capital) are not simply a veil for "real" class relations, but
are the real, fundamental, albeit alienated, relations of that society, which possess a quasi-objective character. Marx's critique of this "fetishism" was central to his argument that his value theory was not metaphysical, but
anti-metaphysical, as it aimed to unmask the social character of what appeared to be natural or objective properties.
Surplus value and prices of production Marx applied the LTV to explain the origin of profit. He argued that under capitalism, the worker's capacity to labor—their "
labor power"—becomes a commodity. Its value, like that of any other commodity, is determined by the labor-time necessary for its reproduction (i.e., the value of the subsistence goods required to maintain the worker). However, the use value of labor-power is that it can create new value. The capitalist buys labor-power at its value but is able to make the worker labor for longer than is necessary to reproduce that value. The value created during this extra, unpaid labor time is "
surplus value", which is the source of profit, rent, and interest. This explanation of exploitation does not rely on cheating or unequal exchange; it occurs even when all commodities, including labor-power, are bought and sold at their values. According to Marx, the sale of labor-power, and the resulting
alienation of the worker's own life-activity, is the key to understanding the dehumanization inherent in capitalism. In Volume III of
Capital (1894), Marx addressed the issue that Ricardo had struggled with: the divergence of prices from values in developed capitalism. He showed that due to competition between capitals, commodities do not sell at their individual values but at "
prices of production", which are equal to their cost-price (cost of materials and wages) plus the average rate of profit on the total capital advanced. This means that capital-intensive industries will receive more profit than the surplus value they produce, while labor-intensive industries will receive less. Marx argued that this did not invalidate the
law of value. Instead, prices of production were simply a "transformed form" of values. The total surplus value produced in the economy determines the total profit, which is then redistributed among capitalists according to the size of their capital. Thus, on the level of the economy as a whole, the sum of prices of production equals the sum of values, and the sum of profits equals the sum of surplus value. Some modern interpretations reframe the transformation not as a problem of converting values to prices, but as a theoretical shift between two levels of analysis: from "production in itself" (Volume I) to the "complex unity of production and circulation" (Volume III). From this perspective, the transformation problem is central to understanding the articulated structure of the capitalist economy, rather than a mere technical puzzle. ==Critique and later developments==