David Ricardo's Contributions to Economics - A synopsis of Ricardo's major theories, by Yousuf Dhamee. Ricardo on Value: The Three Chapter Ones - Three versions of the heavily revised first chapter of Ricardo's book, On Value. From 1817, 1819 and 1821. On the Principles of Political Economy and Taxation - The full text of the third edition of the 1821 book by David Ricardo. Hosted by the Library of Economics and Liberty. David Ricardo and Comparative Advantage - An introduction to Ricardo's theory of comparative advantage and a biography. Archive for the History of Economic Thought: David Ricardo - Contains a bibliography and full text works including an "Essay on Profits," commenting on corn laws, "The High Price of Bullion," on depreciation, and "Principles of Political Economy." Modern History Sourcebook: The Iron Law of Wages - A selection from Ricardo's book, On Wages, describing the labor theory of value.