What Are Monetary Aggregates?

Money aggregates are broad categories that measure the money supply in an economy. In the United States, labels are attributed to standardized monetary aggregates:

  • M0—Physical paper and coin
  • M1—All of M0 plus traveler's checks and demand deposits
  • M2—All of M1, money market shares, and savings deposits

A legacy aggregate known as M3, which includes time deposits over $100,000 and institutional funds, has not been tracked by the Federal Reserve since 2006 but is still calculated by analysts.

Monetary Aggregates Explained

The monetary base (MB or M0) is a monetary aggregate that is not widely observed and differs from the money supply but is nonetheless very important. It includes the total supply of currency in circulation in addition to the stored portion of commercial bank reserves within the central bank. This is sometimes known as high-powered money (HPM) since it can be multiplied through the process of fractional reserve banking.

$3.4 trillion

The size of the U.S. monetary base (M0) as of Q1 2019.

The Federal Reserve uses money aggregates as a metric for how open-market operations, such as trading in Treasury securities or changing the discount rate, affect the economy. Investors and economists observe the aggregates closely because they offer a more accurate depiction of the actual size of a country’s working money supply. By reviewing weekly reports of M1 and M2 data, investors can measure the money aggregates' rate of change and monetary velocity overall.

Key Takeaways

  • A monetary aggregate is a formal way of accounting for money, such as cash or money market funds.
  • Monetary aggregates are used to measure the money supply in a national economy.
  • The monetary base is an aggregate that includes the total supply of currency in circulation plus the stored portion of commercial bank reserves within the central bank.
  • The Federal Reserve uses money aggregates as a metric for how open-market operations affect the economy.

The Impact of Money Aggregates

Studying monetary aggregates can generate substantial information on the financial stability and overall health of a country. For example, monetary aggregates that grow too rapidly may cause fear of over inflation. If there is a greater amount of money in circulation than what is needed to pay for the same amount of goods and services, prices are likely to rise. If over inflation occurs, central banking groups may be forced to raise interest rates or stop the growth in money supply.

The amount of money the Federal Reserve releases into the economy is a preferable indication of a nation's economic health.


For decades, monetary aggregates were essential for understanding a nation's economy and were key in establishing central banking policies in general. The past few decades have revealed that there is less of a connection between fluctuations in the money supply and significant metrics such as inflation, gross domestic product (GDP), and unemployment. The amount of money the Federal Reserve releases into the economy is a clear indicator of the central bank's monetary policy. When compared to GDP growth, M2 is still a useful indicator of potential inflation.

Real World Example

According to The Economist, Sudanese citizens are demanding the resignation of President Omar al-Bashir in response to soaring food prices and an economy with inflation over 70%. These same protests are also occurring in Zimbabwe, where the central bank's bond notes, a type of monetary aggregate, are raising fears of hyperinflation after the government increased fuel prices.

In Africa, a more advanced economy, inflation has decreased over the years. In the 1980s, a fifth of countries south of the Sahara endured average annual inflation of at least 20%. This decade only the two Sudans have high inflation rates.