Essence and merits of David Ricardo’s proof of comparative advantage

Due to a precise definition of comparative advantage and a deeper understanding of the logical interrelationships between this proposition and the two other main elements in David Ricardo’s famous numerical example – the classical rule of specialization and the proposition regarding the non-appliance of the labor theory of value in international exchanges –, it is possible to fully appreciate the merits of his proof of comparative advantage in chapter seven of the Principles. This has important consequences for the longstanding authorship-debate over comparative advantage, because it leads to a more accurate account of the crucial omissions and shortcomings in Robert Torrens’ competing statement in his Essay on the External Corn Trade (1815). Since Torrens fell short of formulating a full proof of the comparative-advantage proposition prior to the publication of the Principles, he is not entitled to the same amount of merit as Ricardo.