Trade Theory and the Roots of Protectionism

The modern case for free trade begins with Adam Smith, who argued in An Inquiry into the Nature and Causes of the Wealth of Nations (1776) that countries benefit from specializing in goods they can produce more efficiently than others, a principle known as absolute advantage. David Ricardo refined this idea in On the Principles of Political Economy and Taxation (1817), showing that even a country with no absolute advantage in anything can still gain from trade by specializing in the goods for which its relative, or comparative, productivity disadvantage is smallest. His classic example, involving England trading cloth for Portuguese wine, remains one of the most influential thought experiments in economics, since it demonstrated that mutually beneficial trade does not require either partner to be the most efficient producer of anything in absolute terms.