l51.
David Ricardo (1817), On the Principles of Political Economy and Taxation. The earliest statement of comparative advantage was probably that of Robert Torrens’ (1815), An Essay on the External Corn Trade, Hatchard. The essence of comparative advantage can be shown by the (notional) case of a nation that can produce everything more efficiently than can any competitor: does such a nation have any incentive to trade? Yes. It is rational for it to purchase the items which it can produce least efficiently and buy them from an overseas supplier, if this allows it to produce more of the items it produces more efficiently. The overall efficiency of the importing nation is thereby increased. This makes perfect sense in a robustly growing world economy stretched to the limit to find ways of producing more with the resources at its disposal. That economy is the inverse of the Lean Economy.