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Money quote:
The aspiration of social science to replicate the predictability and formality of certain natural sciences is, in the end, a hopeless endeavor. Human societies, as Friedrich Hayek, Karl Popper and others understood, are far too complex to model at an aggregate level. Contemporary macroeconomics, despite dealing with social phenomena that are inherently quantified, is today in crisis due to its utter failure to anticipate the recent financial crisis.
Discoverers and Discoveries 