What is the best formula for regulating the money supply?

Here is what G. Edward Griffin responded to a question on the money supply.

Bruce

'WHAT IS THE BEST FORMULA FOR REGULATING THE MONEY SUPPLY?
2013 Dec 23 from Larry Cohen
Dear Mr. Griffin, I'm working on a currency article investigating what would happen if we worked on a set amount of gold, silver, or some other form of money. If we kept the amount at a specific volume, that money would be forced to represent the value of all our production. Would that be a bad thing for us, or a good thing? Should we allow the expansion of our money, or are we better off having a set amount stand for whatever we produce? Do you care to have some input on this?

REPLY FROM GEG:
Hello Larry.
The problem lies in phrases such as "if we kept the amount at a specific volume", "should we allow the expansion of our money" and "would we be better off with a set amount", etc. All of this reveals an underlying assumption that "we" or the state or some authority should have the power to manipulate the money supply according to one of these formulas.

I believe that the money supply should be determined entirely by the forces of supply and demand in a free market, so my answer is that I would not support any of the alternatives mentioned. If the free market were allowed to function, I believe the money supply would expand at almost the exact rate at which the population expands -- so that purchasing power would remain nearly constant or slightly improve over long periods of time.

No man-made formula will work, because all such schemes need to be enforced by coercion. Remove legal-tender laws, and the system will work for the benefit of all.'