Paul De Grauwe The opening sentence of Robert Mundell’s 1963 paper “Capital mobility and stabilization policy under fixed and flexible exchange rates” — one of the two most influential in a series of pathbreaking papers he published in the late 1950s and early 1960s — is curious: “The world is still a closed economy, but its regions and countries are becoming increasingly open.” “Still”? Was Mundell thinking of a future with interplanetary trade, so that eventually the world as a whole wouldn’t be a closed economy? OK, he probably wasn’t, but if he was, it would have been in character. Mundell, who passed away on 4 April, was an economist ahead of his time.