How does the Federal Reserve manage the money supply?

"The most important function of the Federal Reserve System is carrying out monetary policy. The Federal Open Market Committee (FOMC) is the Fed policy-making body that meets eight times a year to make monetary policy decisions. It uses its power to change the money supply in order to control inflation and interest rates, increase employment, and influence economic activity. Three tools used by the Federal Reserve System in managing the money supply are open market operations, reserve requirements, and the discount rate. Open market operations—the tool most frequently used by the Federal Reserve—involve the purchase or sale of U.S. government bonds. The U.S. Treasury issues bonds to obtain the extra money needed to run the government if taxes and other revenues are not enough. In effect, Treasury bonds are long-term loans, five years or longer, made by businesses and individuals to the government. The Federal Reserve buys and sells these bonds for the Treasury. When the Federal Reserve buys bonds, it puts money into the economy. Banks have more money to lend, so they reduce interest rates, which generally stimulates economic activity. The opposite occurs when the Federal Reserve sells government bonds. Banks that are members of the Federal Reserve System must hold some of their deposits in cash in their vaults or in an account at a district bank. This reserve requirement ranges from 3 to 10 percent on different types of deposits. When the Federal Reserve raises the reserve requirement, banks must hold larger reserves and thus have less money to lend. As a result, interest rates rise, and economic activity slows down. Lowering the reserve requirement increases loanable funds, causes banks to lower interest rates, and stimulates the economy; however, the Federal Reserve seldom changes reserve requirements. The Federal Reserve is called “the banker’s bank” because it lends money to banks that need it. The interest rate that the Federal Reserve charges its member banks is called the discount rate. When the discount rate is less than the cost of other sources of funds, such as certificates of deposit, commercial banks borrow from the Federal Reserve and then lend the funds at a higher rate to customers. The banks profit from the spread, or difference, between the rate they charge their customers and the rate paid to the Federal Reserve. Changes in the discount rate usually produce changes in the interest rate that banks charge their customers. The Federal Reserve raises the discount rate to slow down economic growth and lowers it to stimulate growth. In summary, buying government bonds, lowering reserve requirements, or lowering the discount rate increases the money supply, lowers interest rates, and stimulates economic activity. Selling government bonds, raising reserve requirements, or raising the discount rate decreases the money supply, raises interest rates, and slows economic activity."