Ricardian economics is an economic model of international trade introduced by David Ricardo to explain the pattern and the gains from trade in terms of comparative advantage. It assumes perfect competition and a single factor of production: labor, with constant requirements of labor per unit of output that differ across countries.

The neo-Ricardian school is a modern school that is based on a refounding of ideas of value originating in the work of Adam Smith and Ricardo, as reformulated by Piero Sraffa.