Principles of Political Economy and Taxation is the title of a book by David Ricardo on ecomonics. The book is an analysis that concluded land rent grows as population increases. It also clearly laid out the theory of comparative advantage, which showed that all nations could benefit from free trade, even if a nation was less efficient at producing all kinds of goods than its trading partners.

In the preface, Ricardo claimed 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 was ostensibly Ricardo's effort to fill that gap in the economics literature. Regardless of whether the book achieved that goal, it did "secure", according to Ronald Max Hartwell, Ricardo's position among the great classical economists Smith, Thomas Robert Malthus, John Stuart Mill, and Karl Heinrich Marx.

Some of this article's content is derived from the Wikipedia article "David Ricardo".