The concept of mercantilism, popular in the 16th and 17th centuries, focused on countries aiming for trade surpluses to bring in gold. This idea was linked to economic nationalism and a zero-sum approach to international trade. While the emphasis on trade balance was ultimately proven incorrect, mercantilist writers made valuable contributions to economic analysis, including concepts like balance of payments, monetary theory, and exchange rates. Mercantilism also played a role in European colonial activities.