The term "narrow money" typically covers the most liquid forms of money, i.e. currency (banknotes and coins) as well as bank-account balances that can immediately be converted into currency or used for cashless payments (overnight deposits, checking accounts, etc). It is typically denoted as M1. Narrow money is a subset of broad money.
OECD defines "broad money" as: all banknotes and coins; bank deposits not considered long term, i.e. with an agreed maturity of up to 2 years; bank deposits redeemable at notice of up to 3 months, and similar repurchase agreements; money-market fund shares or units; and debt securities maturing within a period of up to 2 years. The typical OECD notation for "broad money" is M3.
Still, the exact definitions of monetary measures depend on the country. The terms will usually be more exactly defined before a discussion, whenever it is not sufficient to assume a wider definition. For the Bank of England, the "inescapable conclusion" is that "there can be no unique definition of 'broad money' and any choice of [a] dividing line between those financial assets included in, and those excluded from, broad money is to a degree arbitrary, and is likely over time to be invalidated by developments in the financial system." Generally, "broad money" is more a term and less a fixed definition across all situations.
However defined in a specific country, the importance of monitoring the development of broad money has been recognized.
- Definition of M0, M1, M2, M3, M4, Financial Times Lexicon
- "Data on the broad monetary aggregate M2 in the US has been subject to several re-definitions" in Calza, Alessandro & João Sousa (2003) "Why has broad money demand been more stable in the Euro area than in other economies?", ECB working paper no.261, September 2003, p. 13 n12
- M1 definition, OECD Data
- O’Brien, Yueh-Yun (2006) "Measurement of Monetary Aggregates Across Countries", Division of Monetary Affairs, Federal Reserve Board, Washington, D.C., 25 November 2006
- Broad money, OECD Data
- Lim, Ewe-Ghee; Sriram, Subramanian (2003). "Factors Underlying the Definitions of Broad Money: An Examination of Recent U.S. Monetary Statistics and Practices of Other Countries" (PDF). IMF. SSRN 879137.
- "Measures of broad money", Bank of England Quarterly Bulletin, 1986 Q2, pp. 212.219
- McPhail, Kim (2010) "Broad Money: A Guide for Monetary Policy," Bank of Canada, October 2010