Comparative advantage is one of the most influential economic theories ever developed,
providing the intellectual foundation for the free trade philosophy which has dominated
political thinking over the last half century through the WTO. Much work has been done
to extend the model to deal with multiple commodities and countries and to examine
the effects of tariffs and imperfect competition. From a maritime perspective the important
issue is the light it casts on why trade has grown so rapidly in the last fifty years.
During this period of free trade improved transport and communications have stimulated
growth by allowing global sourcing and marketing of products. The new technology
also improved the services that support trade. Legally secure documentation, especially
in such areas as establishing the ownership of goods, cheap direct-dialled phone calls,
improved international banking, and more recently e-commerce have made global trading
easier, especially for smaller companies.