The assertion that labor is the sole determinant of value is hard to accept just based upon common sense and experience. The assertion that only labor gives an object value ignores the fact that many natural objects in which no labor has been invested – such as scenic views, pure water, gems and minerals, and wild fruits and vegetables – have economic value. Also the labor theory cannot by its nature account for the fact that people value some natural objects, such as diamonds, tremendously more than other natural objects, such as leaves.
The labor theory of value also fails to take into account changing consumer desires and the contextual nature of value. In a horse-and-buggy culture, horse-shoes are tremendously valuable commodities, but in a society without horses they are virtually useless. Similarly in a society with much leisure time, games and recreational facilities become important, but in a subsistence economy in which people must work nearly continuously just to stay alive, such things may actually have negative value.
The labor theory also ignores the importance of time and position. A 20-year-old wine and properly-aged beef are far more enjoyable than one-year-old wine and unaged beef. Oil in a desert is a potentially valuable resource, but oil in the local reservoir or in the middle of a farmer's field is a hazard.
Perhaps the most grievous theoretical fault with the labor theory is that it ignores what economists call time preference. Time preference is the common strong preference for goods and services here and now, rather than later. Present consumption is more valuable than future consumption.
For example, most workers prefer to be paid when their work is completed rather than when their products are sold – which may be months later. For workers to be paid now, rather than later, someone must advance their wages, and clearly this service has a value. But proponents of the labor theory would have it both ways: workers are to receive the full future value of their product now.
The final theoretical failure of the labor theory of value is the value-effort fallacy. It is folly to assume that all effort produces value. Every day each of us wastes time on fruitless efforts. To equate labor with the automatic creation of value is to fallaciously imply that all human effort is infallible and constantly productive.
Absurdities Of The Labor Theory
The labor theory is even more absurd in practice. If all value is derived from labor, and entrepreneurial effort is "parasitic", who would bother to invest the time and money necessary to build factories, plan product development or organize a production process? If all profits are "exploitation", what incentive does anyone have to risk money on a new and untried product or service? Where will the money come from to finance new investment in tools?
Communist countries have not abolished profits. They have merely transferred all profits to the state, which typically uses them to build a huge military apparatus at the expense of consumer production.
The labor theory of value is violently anti-consumer by its nature. Under this theory, sellers are compelled to price all goods by the amount of labor that goes into them, rather than how much they are demanded by consumers. Thus stores could charge no more for an aged foreign wine than for a local cheap wine (given equal labor input) or more for the work hacked out by a beginner. This inevitably produces a surplus of unskilled and shoddy work, and a shortage of skilled work – which is exactly the situation that exists in communist countries.
The labor theory also means the end of all economic freedom. Engels, Marx's disciple, wrote: "For a pure Marxist society to long endure, voluntary exchange between individuals must be abolished." In a communist society you produce what the rulers tell you and consume what scraps they allow you. If you don't like this, you are of course free to relocate – to a slave labor camp.
Methodological Fallacies
The most interesting fallacies of the labor theory of value are methodological. Labor theory arose from two extremely poor methods of economic research. First it attempted to establish economic laws of exchange by examining only supply – ignoring demand entirely.
Even worse, the entire labor theory is unproven. In the entire first volume of Das Capital, where Marx proposed the labor theory, there is not one "positive proof". Rather Marx offers a fallacious "negative proof" in which he argues:
Premise 1: Some factor in the production of a good gives it value. TRUE;
Premise 2: Only those goods to which man has applied labor have value. FALSE;
Procedure: Examine all the factors producing a good by discarding those which did not create equal value in equal quantity, and end up with one factor – Labor. ARBITRARY;
Conclusion: Labor must be the source of value. FALSE.
Marx promised to provide a positive proof in the Volume 3 of Das Capital. However, that book does not offer a positive proof, and implicitly refutes one. Marx proclaims that two types of capital exist in production, only one of which can produce "surplus value". Thus exchange of items of equal value can have uneven mixtures of these two types of capital, implying that labor alone is not the sole determinant of value.
http://www.isil.org/resources/lit/labor-theory-val.html
I see misunderstandings and outright lies in this, but I do think it important that one test the validity of the LTV before setting out for a deeper grasp of what Marx had to say about capital.