Mystery Theme V by KlionskyG

Question 6

Give the last name of the person who wrote this, excerpted by your Smith. The writer surely would have had much to say about tax havens and online gambling, as well.

This productiveness is determined ... by the average amount of skill of the workmen, the state of science, and the degree of its practical application, the social organisation of production... and by physical conditions. For example, the same amount of labour in favourable seasons is embodied in 8 bushels of corn, and in unfavourable, only in four.

MARX (🇮🇲 Manx) (clue: the Isle of Man is a known tax haven)