An explosion of money is the main reason, but not the only one, to be concerned about last week's surprise decision by the Federal Reserve to increase sharply its holdings of mortgage backed securities and to start purchasing longer term Treasury securities.

First consider the monetary effects. When the Fed purchases public or private securities or makes loans to banks or to other private firms, it must finance them. The Fed can borrow the funds, or it can ask the Treasury to borrow the funds, or it can do it the old-fashioned way: create money. The Fed creates money in part by printing it but mostly by crediting banks with deposits at the Fed. Those deposits are called reserve balances and are the key component – along with currency – of base money or central bank money which ultimately brings about changes in broader money supply measures.

These deposits or reserves have been exploding as the Fed has made loans and purchased securities. Six months ago reserves were $8bn, in a range appropriate for its interest rate target at the time. As of last week, reserves were nearly 100 times larger at $778bn, the result of creating money to finance loans to banks, investment banks, AIG, central banks and purchases of private securities. Before last week's federal open market committee meeting, I projected these would increase to $2,215bn by the end of this year if the new Consumer and Business Loan Initiative of the Treasury were to be financed by money creation. With last week's dramatic announcement, the Fed will have to increase reserves by another $1,150bn to $3,365bn by the end of the year if the securities purchases are financed by money creation. Quantitative easing or credit easing means that the growth rate of the quantity of money increases, but there is no monetary principle or empirical evidence supporting such an explosion.