The Federal Reserve’s conduct of open market operations, its policies related to required reserves and contractual clearing balances, and its lending through the discount window all play important roles in keeping the federal funds rate close to the FOMC’s target rate. Open market operations are the most powerful and often used tool for controlling the funds rate. These operations, which are arranged nearly every business day, are designed to bring the supply of Federal Reserve balances in line with the demand for those balances at the FOMC’s target rate. Required reserve balances and contractual clearing balances facilitate the conduct of open market operations by creating a predictable demand for Federal Reserve balances. If, even after an open market operation is arranged, the supply of balances falls short of demand, then discount window lending provides a mechanism for expanding the supply of balances to contain pressures on the funds rate.
Reserve balance requirements and contractual clearing balances need to be met only on average over a so called reserve maintenance period, not each day. This structure gives depository institutions considerable flexibility in managing their end of day balances at the Federal Reserve from one day to the next. This flexibility helps smooth fluctuations in the federal funds rate. If a depository institution finds that its balance at the Federal Reserve is unexpectedly high on one day (for instance, because a customer made an unexpected deposit or an expected payment was not made), it does not have to offer to lend the extra balance at very low rates. It can absorb the surplus by choosing to hold lower balances in the remaining days of the maintenance period and still meet its balance requirements. Holding a lower balance on a subsequent day of the period does not necessarily increase the likelihood that the depository institution will incur an overnight overdraft if the sum of its required reserve balance and contractual clearing balance is high relative to its payment needs. This flexibility in managing account balances protects against variations in the demand for and supply of Federal Reserve balances that would otherwise put pressure on the federal funds rate.
Reserve balance requirements and contractual clearing balances also help create a predictable demand for balances at the Federal Reserve. Without reserve balance requirements or contractual clearing balances, many depository institutions would still hold positive balances at the Federal Reserve to facilitate payments on behalf of themselves or their customers and to avoid having a negative balance in their account at the end of the day. The exact amount of balances that depository institutions want to hold at the Federal Reserve at the end of the day for clearing purposes can vary considerably from day to day, often depending on the volume and uncertainty of the payment flows through their accounts. These demands are very difficult for the Federal Reserve to forecast. When the level of reserve balance requirements, contractual clearing balances, or the sum of the two make it necessary for depository institutions to hold balances above the shifting and unpredictable level needed for clearing purposes, the Federal Reserve can more accurately determine the demand for Federal Reserve balances and, by manipulating the supply of Federal Reserve balances through open market operations, more readily attain the target funds rate.