Monetary Base is currency in circulation plus banks’ reserve balances at the central bank, as defined by the relevant statistics. Currency means notes and coins; reserves are balances in banks’ central bank accounts, rather than deposits belonging to their ordinary customers.
Your account records how much your bank owes you. The bank may itself hold an account at the central bank, such as the US Federal Reserve, often called the Fed. It uses reserves held there to settle with other banks. A bank’s reserve account is therefore different from a customer’s current account. The monetary base combines these reserves with currency; M1 and M2, by contrast, also include specified types of customer deposits. The base alone cannot tell us how much everyone has available to spend. Broad Money provides a wider view that includes bank deposits. [1]
Money statistics also depend on who holds the cash. In the US H.6 release, currency in the monetary base means cash outside the Treasury and Federal Reserve Banks. It therefore includes cash in commercial banks’ vaults. The currency component of M1 excludes that vault cash. The same phrase, “currency in circulation”, can thus have different coverage in different tables. If vault cash is already included in a total, adding it again counts the same notes twice. [2]
A bank can obtain notes from the central bank in exchange for part of its reserves, a process described by the European Central Bank (ECB). In our simplified example the whole system has currency of 100 and reserves of 200, totalling 300. Exchanging 20 of reserves for cash changes the composition to 120 + 180 = 300. The exchange itself has not increased the base. We assume no other operation occurs alongside it; a new central bank loan would have to be accounted for separately. [4]
Now send a payment to a customer of another bank. In the settlement described by the ECB, reserves move from the sender’s bank to the recipient’s bank. Our example A -30 and B +30 changes the holder, not total reserves. The outflow still matters to the individual bank: it needs the means to settle its payments. An unchanged aggregate base does not mean every bank has enough immediately available funds. [4]
As the Bank of England explains, making a bank loan also creates a corresponding deposit. An illustrative loan of 50 can credit the customer’s account with 50 without simultaneously increasing the monetary base by that amount. The customer has not gained access to the bank’s reserve account. If they transfer the money elsewhere or withdraw cash, the bank must handle settlement. Deposit creation is not unlimited: capital, risk, funding, rules and demand for loans all matter. [5]
A different operation occurs when a central bank buys a security from a non-bank holder: it can increase that holder’s bank’s reserves while the seller receives a deposit. The Bank of England explains why this does not create a fixed multiple of future lending. The ratio of broad money to the base describes a situation, not a guaranteed future conversion. Growth in the base alone cannot determine future credit growth or consumer prices. Banks’, businesses’ and households’ subsequent decisions matter too. [5]
The ECB glossary combines currency with required reserves and excess reserves held in the Eurosystem’s deposit facility, meaning the relevant central bank account. The Eurosystem consists of the ECB and the central banks of countries using the euro. Banks must hold required reserves under the rules; the deposit facility lets them place additional funds with the central bank. A specific statistical series must define the included accounts, holders and period. M0 is sometimes used with a meaning close to monetary base, but the label alone does not establish identical coverage. Before comparing charts, check the definitions and any changes to them. A shared currency or similar indicator name does not necessarily mean you are comparing the same thing. [3]
Bitcoin.org describes a network without a central issuer: an institution that creates new money. Bitcoin (BTC) held directly is neither a claim on a central bank nor another institution’s promise to deliver base money. You authorise spending with private keys: secret data your wallet uses to sign transfers. If a custodian, such as an exchange, holds the keys, an account balance is different from controlling the coins yourself; withdrawals also depend on that custodian. Comparing this with the monetary base helps us ask what we actually hold and whom we have a claim against. It does not establish identical liquidity, meaning how readily money can be accessed or exchanged, or identical price stability or risk across the two systems. [6]
For the clearest picture, read this entry together with Broad Money, M0, M1, M2. The reverse links also lead from Fiat money, Broad Money, M0, M1.