Monetary policy refers to a government’s programs for controlling the amount of money circulating in the economy and interest rates. Changes in the money supply affect both the level of economic activity and the rate of inflation. The Federal Reserve System (the Fed), the central banking system of the United States, prints money and controls how much of it will be in circulation. The money supply is also controlled by the Fed’s regulation of certain bank activities.

When the Fed increases or decreases the amount of money in circulation, it affects interest rates (the cost of borrowing money and the reward for lending it). The Fed can change the interest rate on money it lends to banks to signal the banking system and financial markets that it has changed its monetary policy. These changes have a ripple effect. Banks, in turn, may pass along this change to consumers and businesses that receive loans from the banks. If the cost of borrowing increases, the economy slows because interest rates affect consumer and business decisions to spend or invest. The housing industry, business, and investments react most to changes in interest rates.

As a result of the 2007–2009 recession and the global financial crisis that ensued, the Fed dropped the federal funds rate the interest rate charged on overnight loans between banks to 0 percent in December 2008 and kept the rate at zero until December 2015, when it raised the rate to 0.25 percent. This decision marked the first increase in the federal-funds rate since June 2006, when the federal funds rate was 5.25 percent. As the U.S. economy continues to show a slow but steady expansion, the Fed subsequently increased the federal funds rate to a range of 0.75 to 1 percent in March 2017. As expected, this change has a ripple effect the regional Federal Reserve Banks increase the discount rate they charge commercial banks for short-term loans, many commercial banks raise the interest rates they charge their customers, and credit card companies increase the annual percentage rate (APR) they charge consumers on their credit card balances.

As you can see, the Fed can use monetary policy to contract or expand the economy. With contractionary policy, the Fed restricts, or tightens, the money supply by selling government securities or raising interest rates. The result is slower economic growth and higher unemployment. Thus, contractionary policy reduces spending and, ultimately, lowers inflation. With expansionary policy, the Fed increases, or loosens, growth in the money supply. An expansionary policy stimulates the economy. Interest rates decline, so business and consumer spending go up. Unemployment rates drop as businesses expand. But increasing the money supply also has a negative side more spending pushes prices up, increasing the inflation rate.