Building on the basic lending of previous Banks, Economics shifted radically after the 13th Century. Banks developed multi-national branches and bills of credit, allowing merchants to prepay for a certain foreign currency amount at a fixed rate. Later, insurance and joint-stock ventures entered the economic scene. By the 18th Century, new tools appeared to analyze businesses. With Adam Smith's Wealth of Nations, the notion of markets led to the end of mercantilism and opened a new era of competitive trade.