A Lifelong Friendship: The Correspondence between Oskar Morgenstern and Luigi Einaudi (by Giovanni Pavanelli and Chikako Nakayama ) - This article analyses the intellectual links between Oskar Morgenstern and Luigi Einaudi through an analysis of their correspondence between 1928 and 1961. It focuses on Morgenstern’s formative years, on Einaudi’s role as intellectual mentor and on contemporary debates regarding economic policy. In particular, it examines the period Morgenstern spent in Italy as a Rockefeller Memorial Fellow (June-November 1928), focusing on the scholars he meet and the research projects he undertook. It also analyses his intellectual ties with Einaudi and other Italian economists during the thirties he promoted the translation into German of De Viti de Marco’s I principi dell’economia finanziaria and the publication in the Zeitschrift für Nationalökonomie of several articles by Italian scholary. This work also analyses his participation, together with Einaudi, to the debate on the introduction and the abolition of exchange control in Austria. Key words: Oskar Morgenstern; Luigi Einaudi; Austrian School of Economics; Italian Economic Thought; Exchange Control in Austria.