|A series on Trade| - Non-tariff barriers to trade Most trade
barriers work on the same principle: the imposition of some sort
of cost on trade that raises the price of the traded products.
If two or more nations repeatedly use trade barriers against
each other, then a trade war results. Economists generally agree
that trade barriers are detrimental and decrease overall
economic efficiency, this can be explained by the theory of
comparative advantage. In theory, free trade involves the
removal of all such barriers, except perhaps those considered
necessary for health or national security. In practice, however,
even those countries promoting free trade heavily subsidize
certain industries, such as agriculture and steel. Trade
barriers are often criticized for the effect they have on the
developing world. Because rich-country players call most of the
shots and set trade policies, goods such as crops that
developing countries are best at producing still face high
barriers. Trade barriers such as taxes on food im