If you look at Rothbard’s America’s Great Depression and then the table on page 135, you can see that the total money supply increases by about 61% from 1921 to 1929.
An increase in the money supply does not necessarily cause a depression. What it causes is an increase in prices: say, if the money supply doubles, then all other things being equal, prices will double too, as there are twice as many dollars in circulation for the same amount of goods being traded. However, all other things will usually not be equal; if productive output also doubles over the period during which the money supply has doubled, then there will be twice as many dollars for twice as many goods–and prices will remain unchanged. The price level will only increase if the money supply rises faster than production. A rising money supply can well coexist with declining prices: if the amount of money doubles over a period but production quadruples over the same period, prices will halve.
MV = PQ
where M is the money supply, V is the velocity of money, P the price level, and Q the sum of goods produced and traded for money.
Since there was a tremendous growth in productive output over the 1920s, a 61% increase in money supply does not sound all that horrible.
These Austrian fallacies regarding recessions being caused by money supply are based on the premise that John McVey has identified as false above, namely the confusion between money and credit. The two are very different things.
Money is the means of exchange. An increase in the money supply means that more assets are serving as means of exchange, either by circulating directly (gold coins in people’s wallets) or by virtue of being the subject of circulating claims (gold in bank vaults backing paper bills and checking accounts; real estate and other loan collateral backing paper bills and checking accounts).
Credit is loans that have to be repaid at a specific date in the future–which means that this excludes paper bills and checking accounts, which are redeemable on demand. Credit is when somebody has produced more wealth than he wants to consume at the moment, and is willing to let you use it until he needs it. It does NOT serve as a means of exchange, but is rather a means of renting wealth; its availability does not increase prices, but rather provides opportunities for the borrowers to create more wealth–and thus, supposing an unchanged money supply, indirectly leads to reduced prices.