Born in Belgium in 1911 and educated at the Catholic University of Louvain, Triffin left for the USA in 1935 to pursue an MA at Harvard University. He returned briefly to Belgium, where his decision to go back to the USA to become the first Belgian to earn a PhD at Harvard put him at odds with Léon H. Dupriez, head of the economic research institute at Louvain (along with Fernard Baudhuin and Paul van Zeeland), where Triffin had been a research assistant. Yet his decision to return to the USA in 1939 was propitious, because the Nazis invaded Belgium in 1940. This just-in-time escape from an authoritarian regime is a life experience he shared with Machlup and Fellner.
In his brief biography in the Banca Nazionale del Lavoro Quarterly Review, Triffin acknowledged Joseph Schumpeter, his dissertation adviser, as a major influence on his understanding of pure economic theory. He studied fiscal policy from a Keynesian perspective with John Williamson (whose national key currencies perspective Triffin would not share) and Alvin Hansen (whose perspective on ‘fundamental disequilibrium’ Triffin would embrace). Like Hansen, Triffin believed that a country's balance of payments position might arise from significant internal imbalances (deep recession, low output, high unemployment), which could outweigh balance of payments considerations and point towards major policy changes.