Socially necessary labour time in Marx's critique of political economy is what regulates the exchange value of commodities in trade and consequently constrains producers in their attempt to economise on labour. It doesn't 'guide' them, as it can only be determined after the event and is thus inaccessible to forward planning.
Unlike individual labour hours in the classical labour theory of value formulated by Adam Smith and David Ricardo, Marx's exchange value is conceived as a proportion (or 'aliquot part') of society's labour-time.
Marx did not define this concept in computationally rigorous terms, allowing for flexibility in using it in specific instances to relate average levels of labour productivity to social needs manifesting themselves as monetarily effective market demand for commodities. In addition, although it is axiomatic that socially necessary labour input determines commodity values, precise numerical calculation of such an input in relation to the value of a given commodity, i.e. the empirical regulation of the values of different types of commodities, is exceedingly difficult, due to incessantly shifting social, physical or technical circumstances affecting the labour process.
Read more about Socially Necessary Labour Time: Simplified Explanation of The Concept, Operation of The Law of Value, Marx and Ricardo, Criticism
Famous quotes containing the words socially, labour and/or time:
“It used to be said that, socially speaking, Philadelphia asked who a person is, New York how much is he worth, and Boston what does he know. Nationally it has now become generally recognized that Boston Society has long cared even more than Philadelphia about the first point and has refined the asking of who a person is to the point of demanding to know who he was. Philadelphia asks about a man’s parents; Boston wants to know about his grandparents.”
—Cleveland Amory (b. 1917)
“All’s pathos now. The body that was gross,
Rank, ravenous, disgusting in the act or in repose,
All fever, filth and sweat, its bestial strength
And bestial decay, by pain and labour grows at length
Fragile and luminous.”
—Frank Templeton Prince (b. 1912)
“Farewell deare flowers, sweetly your time ye spent,
Fit, while ye liv’d, for smell or ornament,
And after death for cures.
I follow straight without complaints or grief,
Since if my sent be good, I care not, if
It be as short as yours.”
—George Herbert (1593–1633)