Economists have had an enormous impact on trade policy, and they provide a strong rationale for free trade and for removal of trade barriers. Although the objective of a trade agreement is to liberalize trade, the actual provisions are heavily shaped by domestic and international political realities. The world has changed enormously from the time when David Ricardo proposed the law of comparative advantage, and in recent decades economists have modified their theories to account for trade in factors of production, such as capital and labor, the growth of supply chains that today dominate much of world trade, and the success of neomercantilist countries in achieving rapid growth.
