All labour of a higher or more complicated character than average labour is expenditure of labour-power of a more costly kind, labour-power whose production has cost more time and labour, and which therefore has a higher value, than unskilled or simple labour-power.
 Karl Marx, Das Kapital (1867). copy citation

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Author Karl Marx
Source Das Kapital
Topic cost power
Date 1867
Language English
Reference
Note Translated by Samuel Moore and Edward Aveling
Weblink https://www.marxists.org/archive/marx/works/download/pdf/Capital-Volume-...

Context

“We stated, on a previous page, that in the creation of surplus-value it does not in the least matter, whether the labour appropriated by the capitalist be simple unskilled labour of average quality or more complicated skilled labour. All labour of a higher or more complicated character than average labour is expenditure of labour-power of a more costly kind, labour-power whose production has cost more time and labour, and which therefore has a higher value, than unskilled or simple labour-power. This power being higher-value, its consumption is labour of a higher class, labour that creates in equal times proportionally higher values than unskilled labour does. Whatever difference in skill there may be between the labour of a spinner and that of a jeweller, the portion of his labour by which the jeweller merely replaces the value of his own labour-power, does not in any way differ in quality from the additional portion by which he creates surplus-value.” source