Why do people trade

Why do people trade?  When answering this question consider the history of trade and how trade has influenced history.  Consider the theories of Absolute and Comparative Advantage.  Incorporate thoughts on the Ricardian model, Heckscher (1919) “ Olin (1933) Theory, Leontief Paradox and the New Trade Theory.

need abouut 500 words, references and sitations