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:
“Books, gentlemen, are a species of men, and introduced to them you circulate in the “very best society” that this world can furnish, without the intolerable infliction of “dressing” to go into it. In your shabbiest coat and cosiest slippers you may socially chat even with the fastidious Earl of Chesterfield, and lounging under a tree enjoy the divinest intimacy with my late lord of Verulam.”
—Herman Melville (1819–1891)
“Measure not the work
Until the day’s out and the labour done,
Then bring your gauges.”
—Elizabeth Barrett Browning (1806–1861)
“Little minds mistake little objects for great ones, and lavish away upon the former that time and attention which only the latter deserve. To such mistakes we owe the numerous and frivolous tribe of insect-mongers, shell-mongers, and pursuers and driers of butterflies, etc. The strong mind distinguishes, not only between the useful and the useless, but likewise between the useful and the curious.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)