Excess reserves are bank reserves held by a bank in excess of a reserve requirement for it set by a central bank.
In the United States, bank reserves for a commercial bank are represented by its cash holdings and any credit balance in an account at its Federal Reserve Bank (FRB). Holding excess reserves long term may have an opportunity cost if higher risk-adjusted interest can be earned by putting the funds elsewhere.
For banks in the U.S. Federal Reserve System, excess reserves may be created by a given bank in the very short term by making short-term (usually overnight) loans on the federal funds market to another bank that may be short of its reserve requirements. Banks may also choose to hold some excess reserves to facilitate upcoming transactions or to meet contractual clearing balance requirements.
The total amount of FRB credits held in all FRB accounts for all commercial banks, together with all currency and vault cash, forms the M0 monetary base.
Impact on inflation of excess reserve balances
Research by personnel at the Fed has resulted in claims that interest paid on reserves helps to guard against inflationary pressures. Under a traditional operating framework, in which central bank controls interest rates by changing the level of reserves and pays no interest on excess reserves, it would need to remove almost all of these excess reserves to raise market interest rates. Now when central bank pays interest on excess reserves the link between the level of reserves and willingness of commercial banks to lend is broken. It allows the central bank to raise market interest rates by simply raising the interest rate it pays on reserves without changing the quantity of reserves thus reducing lending growth and curbing economic activity.
Nobel-prize winning economist Eugene Fama contends that paying interest on reserves has (in effect) increased the supply of short-term debt, which through standard demand/supply effects would increase bond yields. The post-GFC low interest-rate environment has therefore persisted in spite of, not because of the actions of the Federal Reserve. Specifically, the demand for risk-free assets (caused by the post-crisis 'flight to quality') has dominated the effect of paying interest on reserves on overall interest rates. He has also argued that paying interest on reserves has protected against hyperinflation of the US dollar.
Interest on excess reserves
In the United States (2008–present) The Financial Services Regulatory Relief Act of 2006 authorized the Federal Reserve Banks to pay interest on balances held by or on behalf of depository institutions at Reserve Banks, subject to regulations of the Board of Governors, effective October 1, 2011. The effective date of this authority was advanced by the Emergency Economic Stabilization Act of 2008.
On October 3, 2008, Section 128 of the Emergency Economic Stabilization Act of 2008 allowed the Federal Reserve banks to begin paying interest on excess reserve balances ("IOER") as well as required reserves. The Federal Reserve banks began doing so three days later. Banks had already begun increasing the amount of their money on deposit with the Fed at the beginning of September, up from about $10 billion total at the end of August, 2008, to $880 billion by the end of the second week of January, 2009.
In comparison, the increase in reserve balances reached only $65 billion after September 11 attacks before falling back to normal levels within a month. Former U.S. Treasury Secretary Henry Paulson's original bailout proposal under which the government would acquire up to $700 billion worth of mortgage-backed securities contained no provision to begin paying interest on reserve balances.
The day before the change was announced, on October 7, 2008, Chairman Ben Bernanke of the Board of Governors of the Federal Reserve System expressed some uncertainty about it, saying, "We're not quite sure what we have to pay in order to get the market rate, which includes some credit risk, up to the target. We're going to experiment with this and try to find what the right spread is." The Fed adjusted the rate on October 22, after the initial rate they set October 6 failed to keep the benchmark U.S. overnight interest rate close to their policy target, and again on November 5 for the same reason.
The Congressional Budget Office estimated that payment of interest on reserve balances would cost the American taxpayers about one tenth of the present 0.25% interest rate on $800 billion in deposits: