Federal Funds Rate - Mechanism

Mechanism

U.S. banks and thrift institutions are obligated by law to maintain certain levels of reserves, either as reserves with the Fed or as vault cash. The level of these reserves is determined by the outstanding assets and liabilities of each depository institution, as well as by the Fed itself, but is typically 10% of the total value of the bank's demand accounts (depending on bank size). In the range of $9.3 million to $43.9 million, for transaction deposits (checking accounts, NOWs, and other deposits that can be used to make payments) the reserve requirement in 2007-2008 was 3 percent of the end-of-the-day daily average amount held over a two-week period. Transaction deposits over $43.9 million held at the same depository institution carried a 10 percent reserve requirement.

For example, assume a particular U.S. depository institution, in the normal course of business, issues a loan. This dispenses money and decreases the ratio of bank reserves to money loaned. If its reserve ratio drops below the legally required minimum, it must add to its reserves to remain compliant with Federal Reserve regulations. The bank can borrow the requisite funds from another bank that has a surplus in its account with the Fed. The interest rate that the borrowing bank pays to the lending bank to borrow the funds is negotiated between the two banks, and the weighted average of this rate across all such transactions is the federal funds effective rate.

The nominal rate is a target set by the governors of the Federal Reserve, which they enforce primarily by open market operations. That nominal rate is almost always what is meant by the media referring to the Federal Reserve "changing interest rates." The actual Fed funds rate generally lies within a range of that target rate, as the Federal Reserve cannot set an exact value through open market operations.

Another way banks can borrow funds to keep up their required reserves is by taking a loan from the Federal Reserve itself at the discount window. These loans are subject to audit by the Fed, and the discount rate is usually higher than the federal funds rate. Confusion between these two kinds of loans often leads to confusion between the federal funds rate and the discount rate. Another difference is that while the Fed cannot set an exact federal funds rate, it can set a specific discount rate.

The federal funds rate target is decided by the governors at Federal Open Market Committee (FOMC) meetings. The FOMC members will either increase, decrease, or leave the rate unchanged depending on the meeting's agenda and the economic conditions of the U.S. It is possible to infer the market expectations of the FOMC decisions at future meetings from the Chicago Board of Trade (CBOT) Fed Funds futures contracts, and these probabilities are widely reported in the financial media.