Theory

Economists debate whether or not a single reserve currency will always dominate the global economy.Many have recently argued that one currency will almost always dominate due to network externalities, especially in the field of invoicing trade and denominating foreign debt securities, meaning that there are strong incentives to conform to the choice that dominates the marketplace. The argument is that, in the absence of sufficiently large shocks, a currency that dominates the marketplace will not lose much ground to challengers.However, some economists, such as Barry Eichengreen argue that this is not as true when it comes to the denomination of official reserves because the network externalities are not strong. As long as the currency's market is sufficiently liquid, the benefits of reserve diversification are strong, as it ensures against large capital losses. The implication is that the world may well soon begin to move away from a financial system dominated uniquely by the dollar. In the first half of the 20th century multiple currencies did share the status as primary reserve currencies. Although Sterling was the largest currency, both francs and marks shared large portions of the market until the First World War, after which the mark was replaced by dollars. Since the Second World War the dollar has dominated official reserves, but this is likely a reflection of the unusual domination of the American economy during this period, as well as official discouragement of reserve status from the potential rivals, Germany and Japan