Litmus test: If you can't describe Ricardo's Law of Comparative Advantage and explain why people find it counterintuitive, you don't know enough about economics to direct any criticism or praise at "capitalism" because you don't know what other people are referring to when they use that word. Eliezer Yudkowsky
Even Ricardo's most famous accomplishment, the law of comparative advantage in foreign trade, is incomplete, though not wrong. Kenneth Arrow
Contemporary theories Ricardo's idea was even expanded to the case of continuum of goods by Dornbusch, Fischer, and Samuelson citation This formulation is employed for example by Matsuyama citation and others. Source: Internet
Paul Samuelson called the numbers used in Ricardo's numerical example dealing with trade between England and Portugal the "four magic numbers". Source: Internet
A. Maneschi, The True Meaning of Ricardo's Four Magic Numbers, Journal of International Economics, 62: 433-443. Source: Internet
Criticism of the Ricardian theory of trade Ricardo's argument in favour of free trade has been attacked by those who believe trade restriction can be necessary for the economic development of a nation. Source: Internet