"For hundreds of years, many economists believed that the value of a good depended on the cost of producing it. In particular, many subscribed to the labor theory of value, which argued that a good’s value derived from the amount of work that went into making it.
Much like the geocentric view of the universe, the labor theory of value had some superficial plausibility, as it does often seem that goods that involve more labor have more value. However, much like the story in astronomy, the theory got increasingly complicated as it tried to explain away some obvious objections.
Today, the labor theory of value has only a minuscule number of adherents among professional economists, but it remains all too common in other academic disciplines when they discuss economic issues, as well as among the general public.
value is subjective. That is, the value of a good is not determined by the physical inputs, including labor, that helped to create it. Instead, the value of a good emerges from human perceptions of its usefulness for the particular ends that people had at a particular point in time. Value is not something objective and transcendent. It is a function of the role that an object plays as a means toward the ends that are part of human purposes and plans."
Trecho retirado de "We're Still Haunted by the Labor Theory of Value"