2016 Reprint of 1911 Edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. First published in 1817, this title established Ricardo as an important political economist. He concludes that land rent grows as population increases. He also presents the theory of comparative advantage, the theory that free trade between two or more countries can be mutually beneficial, even when one country has an absolute advantage over the other countries in all areas of production. Ricardo claims in the preface that Turgot, Stuart, Adam Smith, Jean-Baptiste Say, Sismondi, and others had not written enough "satisfactory information" on the topics of rent, profit, and wages. "Principles of Political Economy" is Ricardo's effort to fill that gap in the literature. Regardless of whether the book achieved that goal, it secured Ricardo's position among the great classical economists Adam Smith, Thomas Robert Malthus, John Stuart Mill, and Karl Marx.