"I cannot forbear to lengthen an already long paper by adding some remarks about what Paul Krugman calls the "new international economics" (Strategic Trade Policy and the New International Economics, MIT paperback, 1986) and "new trade theory" (in "New Trade Theory and the Less Developed Countries," a paper submitted to the Carlos F. Diaz-Alejandro memorial conference held in Helsinki, August 23-5, 1986). The "new" theory rests on economies of scale. As I told Krugman at Helsinki, I find it a bizarre notion that increasing returns in international trade are new. I developed it at length in my 1953 textbook, based on the 1929 article of John Williams, reprinted in the AEA, "Readings in the Theory of International Trade." Jan Tinbergen developed it in his textbook, International Economic Integration (1954). I recall the joy in Cambridge, Massachusetts, when Kenneth Arrow made increasing returns respectable by formalizing Alfred Marshall's description of long-run decreasing costs historically with his paper on "Learning by Doing," a paper rapidly incorporated into international-trade theory by those who need formal models to understand the intuitively obvious. I confess to some irritation over Krugman's defense of his international-trade theory as new because it offers a well-worn truth in equation form."