Ever since David Hume introduced his price-specie flow mechanism in 1752, the question of external adjustment has been a classic issue for international macroeconomists. In 1968 Robert Mundell asked “To what extent should surplus countries expand, to what extent should deficit countries contract?” (Mundell, 1968). The debate in those days was about the relative merits of expenditure-switching and expenditure-reducing policies, analyzed within the useful template of the Mundell-Fleming model. Subsequent research introduced microfoundations, added an explicit dynamic dimension borrowed from optimal growth theory, and highlighted the role of expectations. Throughout this process, understanding the adjustment of a country’s external balances remained a key issue. By the early 1980s a modern synthesis had emerged, in the form of the intertemporal approach to the current account.