On the Magic Behind David Ricardo's Four Mystical Numbers

Building on Ruffin's recent interpretation of Ricardo's four numbers as labour embodied in trade rather than domestic labour coefficients, I identify the magic behind these four mystical numbers. I show that the magic lies in Ricardo's underlying logic in predicting the pattern of international trade. Using a single graphical framework, I show that Ricardo's logic provides a device for a unified treatment of the commodity and the factor content predictions of international trade with an arbitrary number of goods, factors and countries.