The Dornbusch-Fischer-Samuelson model comes from a paper titled first for this concept that extends the classical idea of it to a continuum of goods. Gottfried Haberler’s work on this concept, which Robert Torrens independently discovered, detached it from the earlier labor theory of value. A “revealed” form of this economic concept, (-5[1])which is defined by the Balassa index, is based on flows of goods. A theory that this concept is the (*) main driver of gains from trade, even if one country has higher efficiency in all goods, was illustrated with examples of English cloth and Portuguese wine by David Ricardo. For 10 points, name this economic state of having a lower opportunity cost and so being best placed to produce a certain good, unlike in an “absolute” form. ■END■ (10[1])