Why are Banks Holding so Many Excess Reserves?

The buildup of reserves in the U.S. banking system during the financial crisis has fueled concerns that the Federal Reserve's policies may have failed to stimulate the flow of credit in the economy: Banks, it appears, are amassing funds rather than lending them out. However, a careful examination of the balance sheet effects of central bank actions shows that the high level of reserves is simply a by-product of the Fed's new lending facilities and asset purchase programs. The total quantity of reserves in the banking system reflects the scale of the Fed's policy initiatives, but conveys no information about the initiatives' effects on bank lending or on the economy more broadly