Commodity money

Commodity money's ability to function as a store of value is also limited by its very nature. Copper and tin risk rust and corrosion. Gold and silver are soft metals that can lose weight through scratches and abrasions.

Stability aside, commodity-based currencies may have a tendency to restrain growth in a very active economy. For example, in order to maintain the price level, the supply of money in an any economy must be equal or greater than the volume of goods and services produced. If commodities are used as money, then the total production can easily outstrip the supply of those commodities, which leads to price deflation. The lower prices of goods would signal to their producers to reduce the supply of goods, hence restoring the price level. As such, production within commodity-based economies tends to be limited by the supply of the commodity currency.

This problem is compounded by the fact that money also serves as a store of value. This encourages hoarding and takes the commodity money out circulation, reducing the supply. The supply of circulating commodity currency is further reduced by the fact that commodity moneys also have competing non-monetary uses. For example, gold and silver are used in jewelry, and nickel and copper have important industrial uses.

Commodity based currencies also limit the geographic extent of the trading market. To make large purchases either a large volume or a high weight or both of the commodity must be transported to the seller. The cost of transportation of the currency raises the transaction cost and makes long distance sales less attractive.