Monetary theory is where Austrians diverge the most from mainstream. Mises built a new taxonomy of money. He said money included any checking account deposits. The marginal utility of gold on the last day of barter was determined by the uses of gold. People then demanded gold as money because there was preexisting value. A paper dollar must have such a connection to money. Government cannot create money. Money is not neutral. The natural trend of prices in a market economy is falling.