The U.S. dollar has played a preeminent role in the global economy since the second World War. It is used as a reserve currency and the currency of denomination for a large fraction of global trade and financial transactions. The status of the U.S. dollar engenders important considerations for the effectiveness of U.S. policy instruments and the functioning of global financial markets. These considerations include understanding potential factors that may alter the dominance of the U.S. dollar in the future, such as changes in the macroeconomic and policy environments or the development of new technologies and payment systems.