In the United States, its supply is divided into M1, M2, and M3 by the Federal Reserve.
Simon Newcomb helped to develop the "quantity theory" of this. Ludwig von Mises wrote a book about the theory of this and credit, and according to the Fisher Equation, the amount of it can be determined by dividing PT by V, which stands for its velocity. In the United States, its supply is divided into M1, M2, and M3 by the Federal Reserve. Inflation causes its purchasing power to decrease. For 10 points, name this keystone of the economy, whose examples include coins and dollar bills.
Simon Newcomb helped to develop the "quantity theory" of this.
money [accept currency or clear-knowledge equivalents]