who, with Adam Smith, founded British classical economics. In 1819–23 he was an MP, supporting Free Trade, a return to the gold standard, and the repeal of the Corn Laws. He is best remembered for his Principles of Political Economy and Taxation (1817), arguing that the value of a commodity is related to amount of labour required to make it—a premise later adopted by Karl Marx. He also formulated the law of comparative advantage in international trade.