The so-called Ricardian trade model of contemporary economic textbooks is not a rational reconstruction of Ricardo's famous numerical example in chapter seven of the Principles. It differs from the latter in terms of the definition of the four numbers, relevant cost comparison, rule for...

David Ricardo indicated in his famous numerical example in the Principles that it would be advantageous to Portugal to import English cloth made by 100 men, although it could have been produced locally with the labor of only 90 Portuguese men. As the production of the cloth required less...