Date of Birth: April 19, 1772
Date of Death: September 11, 1823

Successor to Adam Smith's pre-eminent position in British economics, his influence continued to dominate the aims and methods of the discipline throughout the nineteenth century. Despite his own considerable practical experience, his writings are severely abstract and frequently difficult. His chief emphasis was on the principles of diminishing returns in connection with the rent of land, which he believed also regulated the profits of capital. He attempted to deduce a theory of value from the application of labor, but found it difficult to separate the effects of changes in distribution from changes in technology.

Ricardo's law of rent was probably his most notable and influential discovery. It was based on the observation that the differing fertility of land yielded unequal profits to the capital and labor applied to it. Differential rent is the result of this variation in the fertility of land. This principle was also noted at much the same time by Malthus, West, Anderson and others. His other great contribution, the law of comparative cost, or comparative advantage, demonstrated the benefits of international specialization of the commodity composition of international trade. This was at the root of the free trade argument which set Britain firmly on the course of exporting manufactures and importing foodstuffs. His success in attaching other economists, particularly James Mill and McCulloch, to his views largely accounted for the remarkable dominance of his ideas long after his own lifetime.