When Rogério Zandamela steps down from the helm of the Bank of Mozambique, he will leave behind a portrait that, at first glance, seems almost immaculate. Inflation has been broadly stable, and international reserves have been rebuilt after years of turbulence. It is the kind of photograph any central banker would proudly frame on the wall upon departure. Yet, as is often the case in monetary policy, the frame hides more than it reveals. The sacrifice rate, that is, the amount of economic growth a country forfeits for every percentage point of inflation reduced, is the invisible number in Zandamela’s farewell narrative. And it is invisible for a reason: it shows that stability was not free. According to Mozambique’s National...