Labor Theory of Value
The labor theory of value is a major pillar of traditional Marxian economics, which is evident in Marx’s masterpiece, Capital (1867). The theory’s basic claim is simple: the value of a commodity can be objectively measured by the average number of labor hours required to produce that commodity.
If a pair of shoes usually takes twice as long to produce as a pair of pants, for example, then shoes are twice as valuable as pants. In the long run, the competitive price of shoes will be twice the price of pants, regardless of the value of the physical inputs.
Although the labor theory of value is demonstrably false, it prevailed among classical economists through the midnineteenth century. Adam Smith, for instance, flirted with a labor theory of value in his classic defense of capitalism, The Wealth of Nations (1776), and David Ricardo later systematized it in his Principles of Political Economy (1817), a text studied by generations of free-market economists.