Concept
Equation of exchange
Related concepts (4)
Quantity theory of money
In monetary economics, the quantity theory of money (often abbreviated QTM) is one of the directions of Western economic thought that emerged in the 16th-17th centuries. The QTM states that the general price level of goods and services is directly proportional to the amount of money in circulation, or money supply. For example, if the amount of money in an economy doubles, QTM predicts that price levels will also double.
Velocity of money
The velocity of money measures the number of times that the average unit of currency is used to purchase goods and services within a given time period. The concept relates the size of economic activity to a given money supply, and the speed of money exchange is one of the variables that determine inflation. The measure of the velocity of money is usually the ratio of the gross national product (GNP) to a country's money supply. If the velocity of money is increasing, then transactions are occurring between individuals more frequently.
Deflation
In economics, deflation is a decrease in the general price level of goods and services. Deflation occurs when the inflation rate falls below 0% (a negative inflation rate). Inflation reduces the value of currency over time, but sudden deflation increases it. This allows more goods and services to be bought than before with the same amount of currency. Deflation is distinct from disinflation, a slow-down in the inflation rate, i.e. when inflation declines to a lower rate but is still positive.
Money supply
In macroeconomics, the money supply (or money stock) refers to the total volume of currency held by the public at a particular point in time. There are several ways to define "money", but standard measures usually include currency in circulation (i.e. physical cash) and demand deposits (depositors' easily accessed assets on the books of financial institutions). The central bank of a country may use a definition of what constitutes legal tender for its purposes.