Metallic money

Monetary theory
The relation between money and what it will buy has always been a central issue of monetary theory. Crucial to understanding this matter is the distinction economists make between face (or nominal) values and real values—that is, between official values stated in current dollars, pesos, pounds, yen, euros, and so on and the same quantities adjusted by the price level. The latter is a “real” value, meaning the real quantity of goods, services, and assets that money will buy. This can also be understood as the real purchasing power of the money stock.
The demand for money
Economists have generally held that the level of prices is determined mainly by the quantity of money. But precisely how the quantity of money affects the level of prices and what the effects are of changes in the quantity of money have been conceptualized in different ways at different times. There are two principal issues to consider. First, what determines the demand for money (the amount of money that the public willingly holds)? And second, how do changes in the stock of money affect the price level and other nominal values?
A government or its central bank determines the nominal quantity of money that circulates and is held, but the public determines money’s real value. If the central bank provides more money than the public wants to hold, the public spends the excess on goods, services, or assets. While the additional spending cannot reduce the nominal money stock, this spending will bid up the prices of nonmoney objects, because too much money is chasing the limited stock of goods and assets. The subsequent rise in prices will lower the real value of the money stock until the public possesses the real value it desires to hold in the aggregate. Conversely, if the central bank provides less money than the public desires to hold, spending slows. Prices fall, thereby raising the quantity of real balances.
The amount of desired real balances for a country (that is, the real value of money within a country) is not a fixed number. It depends on the opportunity cost of holding money, the direct return earned when holding money, and income or wealth. A short-term interest rate is the usual measure of the opportunity cost of holding money, but money holders participate in many different markets, so other relative prices may affect real money holdings. Inflation increases market interest rates and thus raises the opportunity cost of holding money. In countries experiencing rapid inflation, the real value of the money stock shrinks because people choose to hold less of their wealth in this form. If inflation is brought to a halt, however, the opportunity cost of holding money will drop, and real balances will rise.
Inflation has a particularly strong effect on the demand for money because currency pays no interest, and checking deposits typically receive little or no interest return. (Most of the direct return to money balances takes the form of transaction services and convenience.) As the opposite of inflation, deflation raises the return on money that is held by giving each nominal unit greater command over goods and assets. Consumer spending will thus decrease as people hold onto their money in expectation of lower prices in the future. Other phenomena affecting the amount of money that people willingly hold include income, wealth, and some measure of transactions volume. Increases in the real value of these measures will be followed by increases in the amount of real balances.