Currency board Helena continue to operate currency boards, backing their locally printed currency notes with pound sterling reserves. A gold standard is a special case of a currency board where the value of the national currency is linked to the value of gold instead of a foreign currency. For a precise definition of what constitutes a currency board, including past examples, see: Currency board A currency board is a monetary authority which is required to maintain a fixed exchange rate with a foreign currency. This policy objective requires the conventional objectives of a central bank to be subordinated to the exchange rate
World currency a single world currency is unnecessary, because the U.S. dollar is providing many of the benefits of a world currency while avoiding some of the costs. If the world does not form an optimum currency area, then it would be economically inefficient for the world to share one currency. In the present world, nations are not able to work together closely enough to be able to produce and support a common currency. There has to be a high level of trust between different countries before a true world currency could be created. A world currency might even undermine national sovereignty