Real Bills Doctrine - Convertibility

Convertibility

Two kinds of convertibility must be distinguished:

Physical convertibility

A unit of paper or credit money (a “dollar”) can be presented to the issuing bank in exchange for a physical amount of gold, silver, or some other commodity.

Financial convertibility

A dollar can be returned to the issuing bank in exchange for a dollar’s worth of the bank’s assets.

The importance of financial convertibility can be seen by imagining that people in a community one day find themselves with more paper currency than they wish to hold — for example, when the Christmas shopping season has ended. If the dollar is physically convertible (for one ounce of silver, let us suppose), people will return the unwanted dollars to the bank in exchange for silver, but the bank could head off this demand for silver by selling some of its own bonds to the public in exchange for its own paper dollars. For example, if the community has $100 of unwanted paper money, and if people intend to redeem the unwanted $100 for silver at the bank, the bank could simply sell $100 worth of bonds or other assets in exchange for $100 of its own paper dollars. This will soak up the unwanted paper and head off peoples’ desire to redeem the $100 for silver.

By conducting this type of open market operation — selling bonds when there is excess currency and buying bonds when there is too little — the bank can maintain the value of the dollar at one ounce of silver without ever redeeming any paper dollars for silver. In fact, this is essentially what all modern central banks do, and the fact that their currencies might be physically inconvertible is made irrelevant by the maintenance of financial convertibility. Note that financial convertibility cannot be maintained unless the bank has sufficient assets to back the currency it has issued. Thus, it is an illusion that any physically inconvertible currency is necessarily also unbacked.