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The Federal Reserve System and public- and private-sector analysts have long monitored the growth of the money supply because of the effects that money supply growth is believed to have on real economic activity and on the price level. Over time, the Fed has tried to achieve its macroeconomic goals of price stability, sustainable economic growth, and high employment in part by influencing the size of the money supply. In the past few decades, however, the relationship between growth in the money supply and the performance of the U.S. economy has become much weaker, and emphasis on the money supply as a guide to monetary policy has waned.
Money Supply Measures
The money supply measures reflect the different degrees of liquidity—or spendability—that different types of money have. The narrowest measure, M1, is restricted to the most liquid forms of money; it consists of currency in the hands of the public; travelers checks; demand deposits, and other deposits against which checks can be written. M2 includes M1, plus savings accounts, time deposits of under $100,000, and balances in retail money market mutual funds.
The chart below shows the relative sizes of the two monetary aggregates. In April 2008, M1 was approximately $1.4 trillion, more than half of which consisted of currency. While as much as two-thirds of U.S. currency in circulation may be held outside the United States, all currency held by the public is included in the money supply because it can be spent on goods and services in the U.S. economy. M2 was approximately $7.7 trillion and largely consisted of savings deposits.
The Full Employment and Balanced Growth Act of 1978, known as the Humphrey-Hawkins Act, required the Fed to set one-year target ranges for money supply growth twice a year and to report the targets to Congress. During the heyday of the monetary aggregates, in the early 1980s, analysts paid a great deal of attention to the Fed's weekly money supply reports, and especially to the reports on M1. If, for example, the Fed released a higher-than-expected M1 figure, the markets surmised that the Fed would soon try to curb money supply growth to bring it back to its target, possibly increasing short-term interest rates in the process.
Following the introduction of NOW accounts nationally in 1981, however, the relationship between M1 growth and measures of economic activity, such as Gross Domestic Product, broke down. Depositors moved funds from savings accounts—which are included in M2 but not in M1—into NOW accounts, which are part of M1. As a result, M1 growth exceeded the Fed's target range in 1982, even though the economy experienced its worst recession in decades. The Fed de-emphasized M1 as a guide for monetary policy in late 1982, and it stopped announcing growth ranges for M1 in 1987.
By the early 1990s, the relationship between M2 growth and the performance of the economy also had weakened. Interest rates were at the lowest levels in more than three decades, prompting some savers to move funds out of the savings and time deposits that are part of M2 into stock and bond mutual funds, which are not included in any of the money supply measures. Thus, in July 1993, when the economy had been growing for more than two years, Fed Chairman Alan Greenspan remarked in Congressional testimony that "if the historical relationships between M2 and nominal income had remained intact, the behavior of M2 in recent years would have been consistent with an economy in severe contraction." Chairman Greenspan added, "The historical relationships between money and income, and between money and the price level have largely broken down, depriving the aggregates of much of their usefulness as guides to policy. At least for the time being, M2 has been downgraded as a reliable indicator of financial conditions in the economy, and no single variable has yet been identified to take its place."
A variety of factors continue to complicate the relationship between money supply growth and U.S. macroeconomic performance. For example, the amount of currency in circulation rose rapidly in late 1999, as fears of Y2K-related problems led people to build up their holdings of the most liquid form of money, and then it showed no increase (even on a seasonally adjusted basis) in the first half of 2000. Also, the size of the M1 aggregate has been held down in recent years by "sweeps"—the practice that banks have adopted of shifting funds out of checking accounts that are subject to reserve requirements into savings accounts that are not subject to reserve requirements.
In 2000, when the Humphrey-Hawkins legislation requiring the Fed to set target ranges for money supply growth expired, the Fed announced that it was no longer setting such targets, because money supply growth does not provide a useful benchmark for the conduct of monetary policy. However, the Fed said, too, that "…the FOMC believes that the behavior of money and credit will continue to have value for gauging economic and financial conditions." Moreover, M2, adjusted for changes in the price level, remains a component of the Index of Leading Economic Indicators, which some market analysts use to forecast economic recessions and recoveries.
In March 2006, the Federal Reserve Board of Governors ceased publication of the M3 monetary aggregate. M3 did not appear to convey any additional information about economic activity that was not already embodied in M2. Consequently, the Board judged that the costs of collecting the data and publishing M3 outweigh the benefits.