First, a medium of exchange is different from a money supply. When the medium of exchange is in proper balance, the media of exchange circulating (what people want to call money supply) equals desire to trade. The medium of exchange facilitates trading activity at whatever it naturally wants to be.
That said, a properly managed medium of exchange behaves according to the relation:
DEFAULT = INTEREST + INFLATION
The manager makes loans of exchange media; he measures DEFAULT; and he collects INTEREST in direct balance to DEFAULT. By so doing, he assures INFLATION of his media is zero.
The manager of the medium measures the “requisite number” which is DEFAULT experienced. It’s not a plugged number, it’s an easily measured number. And to maintain balance, the manager collects INTEREST equal to that number.
As I have shown, gold can not be money because the manager of the exchange medium can not adjust the amount of gold to equal the desired trading activity. That’s exactly the problem. If trade becomes more brisk, the medium manager (the market actually) can only adjust the trading value of the media. In the case of gold this means less gold trades for more stuff. Further, it means someone can trade a can of beans for some gold today and at some later day can acquire more than one can of beans for that same gold. Why, because the gold must now support more traders and becomes value in-and-of itself. This is a violation of the relation governing a medium of exchange.
We have the opposite problem with an unbacked medium of exchange not managed by the relation (i.e. our system today). Because DEFAULT can and does exceed INTEREST in our system, we have INFLATION. It means someone can trade a can of beans for some dollars today and at some later day can not acquire a full can of beans for those same dollars.
Anyone can create a medium of exchange. All that is required is to have your media become trusted. Bankers in the olden days garnered (and abused) this trust. But if you openly manage the medium which you create and follow the relation and are totally open with your lending activity, DEFAULT experience, and INTEREST collections your medium will be naturally trusted and used. Why? Because INTEREST will be competitively low, exchange media will be in free supply, responsible traders will be favored and fairly treated, and INFLATION will be zero.
It’s very much like running an insurance business. All the same prudent mechanisms need to be employed. However, the big difference is this: with insurance, the agreement is between just you and the insurance company. With an exchange medium, the agreement is between the manager of the medium and the entire economy using the media to facilitate trade. That’s why we can have many insurance companies but we can’t have many managers of exchange medium.
Right now we sort of have several managers of exchange media. They are American Express, Master Card, Visa, Discover, Carte Blanche, and Diner’s Club. To a lesser extent we have the old banking system with its demand deposits and checks. These are kind of retailers. Unfortunately, the wholesaler is the Fed and the US Treasury. They are not following the relation DEFAULT = INTEREST + INFLATION so the system is being gamed and we are all being cheated through INFLATION and/or high INTEREST as a result. The responsible traders (i.e. those who don’t default) must cover for the irresponsible traders and must feed the parasites operating the system who demand tribute with every transaction.
Whether by design or ineptitude, the Fed and Treasury cause the so-called business cycle. If they had to follow the relation there would be no business cycles.