[damptowel]

This is a commonly held belief, but it's wrong, the dominant economic models in use today are neither rigorous (internally inconsistent, extremely poor empirical verification, major aggregation errors, lack of essential inputs) nor representative of an economy (a dynamic system, not an extremely stylized static equillibrium model). You should read Keen's book, it's point is not that those assumptions don't always hold, it's that they under _any_ real world circumstance will invalidate themselves.