foozhencheng 发表于 2015-12-31 22:56 
https://en.wikipedia.org/wiki/Labor_theory_of_value#Criticisms
A generalization of labor theory of value[edit]
To resolve the above mentioned contradiction of the theory with reality, some authors[52][53][54] proposed to reconsider the role of production equipment (constant capital) in production of value, following hints in Das Kapital, where Marx [8] described the functional role of machinery in production processes in Chapter XV (Machinery and Modern Industry) in the following words:
On a closer examination of the working machine proper, we find in it, as a general rule, though often, no doubt, under very altered forms, the apparatus and tools used by the handicraftsmen or manufacturing workman: with this difference that instead of being human implements, they are the implements of a mechanism, or mechanical implements (pp. 181-182). The machine proper is therefore a mechanism that, after being set in motion performs with its tools the same operations that were formerly done by the workman with similar tools. Whether the motive power is derived from man or from some other machine, makes no difference in this respect (p. 182). The implements of labour, in the form of machinery, necessitate the substitution of natural forces for human force, and the conscious application of science instead of rule of thumb (p. 188). After making allowance, both in the case of the machine and of the tool, for their average daily cost, that is, for the value they transmit to the product by their average daily wear and tear, and for their consumption of auxiliary substances such as oil, coal and so on, they each do their work gratuitously, just like the forces furnished by nature without the help of man (p. 189).
These words state that one has to account, while interpreting production of value, that the workers' efforts in production of things are substituted with work of production equipment with due effect. Really, at substitution of labourer's work by forces of the nature, that is at substitution of efforts of people by work of external forces of the nature by means of the production equipment, work operates in a complex as workers' efforts plus work of the equipment. Thus, work of machines can be appreciated only so far as this work does what people wish, replacing their efforts and, consequently, a measure of value, certainly, can be the labourers' work only. It is possible to tell also, according to Marx, that only labourers' work creates value, but Marx, unfortunately, had not completed the theory of substitution to the logical end. Taking into account the effect of substitution, one can say that the only universal and accurate measure of value is the work of labourers or other agents used for production.
So, we one has to complete the labour theory of value with the law of substitution, and a new important concept of substitutive work, as a value-creating production factor, has to be introduced and used to formulate the theory, which investigates processes of emerging, motion and disappearing of value, being hardly interested in its material carriers.