Sources of the Money Supply | 货币供应的来源

📚 Sources of the Money Supply | 货币供应的来源

In Cambridge A-Level Economics, the money supply is the total stock of money circulating in an economy at a given time. It includes cash held by households and firms, as well as deposits in banks that can be used for transactions. Understanding where money comes from helps explain inflation, interest rates, aggregate demand and the effectiveness of monetary policy.

在剑桥 A-Level 经济学中，货币供应是指某一特定时期内经济中流通的货币总存量。它包括家庭和企业持有的现金，以及可用于交易的银行存款。理解货币的来源有助于解释通货膨胀、利率、总需求和货币政策的有效性。

---

1. Definition and Measures of Money Supply | 货币供应的定义与衡量

The money supply can be defined narrowly or broadly. Narrow money includes notes, coins and sight deposits that can be converted into cash immediately. Broad money adds time deposits, savings accounts and other liquid financial assets held by the private sector.

货币供应可以狭义或广义地定义。狭义货币包括纸币、硬币和可立即变现的活期存款。广义货币则加上定期存款、储蓄账户以及私人部门持有的其他流动性较高的金融资产。

Measure (指标)	Components (组成部分)	Policy use (政策用途)
Narrow money / M0 (狭义货币)	Currency in circulation plus banks’ reserves at the central bank	Shows the immediate monetary base
M1 (M1)	Notes, coins and sight deposits	Measures immediate spending power
M4 / broad money (M4 / 广义货币)	Notes, coins and all private-sector deposits, including time and savings accounts	Used by central banks to assess longer-term liquidity

Different measures matter because policy-makers watch narrow money for immediate spending power and broad money for longer-term liquidity and credit conditions.

不同衡量指标都很重要，因为政策制定者关注狭义货币以了解即期购买力，关注广义货币以了解长期流动性和信贷状况。

---

2. The Monetary Base: High-Powered Money | 基础货币：高能货币

The monetary base, also called high-powered money or M0, is the foundation of the money supply. It consists of currency in circulation and commercial banks’ reserves held at the central bank.

基础货币，又称高能货币或 M0，是货币供应的基础。它由流通中的货币和商业银行在中央银行的准备金组成。

H = C + R

In this equation, H represents the monetary base, C represents currency held by the public, and R represents reserves held by banks. Changes in any component alter the base and can trigger multiple expansion or contraction of deposits throughout the banking system.

在该等式中，H 表示基础货币，C 表示公众持有的现金，R 表示银行持有的准备金。任何组成部分的变化都会改变基础货币，并可能引发整个银行体系存款的倍数扩张或收缩。

---

3. Central Bank Issuance of Notes and Coins | 中央银行发行纸币与硬币

The central bank has the monopoly right to issue notes and coins in most modern economies. When it prints new currency and injects it into the banking system through open market operations or lending to banks, the monetary base increases directly.

在大多数现代经济体中，中央银行拥有发行纸币和硬币的垄断权。当它印制新货币并通过公开市场操作或向银行放贷将其注入银行体系时，基础货币会直接增加。

However, printing cash alone is not the main source of money supply growth in modern economies. The larger source is deposit creation by commercial banks through lending. Central bank cash forms only a small fraction of broad money.

然而，在现代经济中，单纯印制现金并不是货币供应增长的主要来源。更大的来源是商业银行通过贷款进行的存款创造。中央银行发行的现金只占广义货币的一小部分。

---

4. Commercial Bank Credit Creation | 商业银行的信用创造

Commercial banks create money when they make loans. A loan is granted by crediting the borrower’s deposit account, which increases the total stock of bank deposits. This process is called credit creation, and it is the most important source of broad money growth.

商业银行在发放贷款时创造货币。贷款通过记入借款人存款账户的方式发放，这会增加银行存款总量。这一过程称为信用创造，是广义货币增长的最重要来源。

Suppose the required reserve ratio is 10% and a customer deposits 1,000 units in Bank A. Bank A keeps 100 as reserves and lends 900. The borrower spends the 900, and it is deposited in Bank B, which keeps 90 and lends 810, and so on.

假设法定准备金率为 10%，一名客户在 A 银行存入 1,000 单位。A 银行保留 100 作为准备金并贷出 900。借款人花掉这 900，它被存入 B 银行，B 银行保留 90 并贷出 810，如此循环。

Total deposits = Initial deposit × (1 ÷ Reserve ratio)

总存款 = 初始存款 ×（1 ÷ 准备金率）

With a 10% reserve ratio, the maximum total deposit creation is 1,000 × (1 ÷ 0.1) = 10,000 units. The initial 1,000 units of new money have multiplied into a much larger money supply. This shows that loans create deposits, not the other way round.

在 10% 的准备金率下，最大存款创造总额为 1,000 ×（1 ÷ 0.1）= 10,000 单位。初始的 1,000 单位新货币成倍扩大为更大的货币供应量。这表明贷款创造存款，而不是相反。

---

5. The Money Multiplier | 货币乘数

The money multiplier shows how much broad money can be created from a given monetary base. In a simple model with a fixed reserve ratio, the multiplier is the reciprocal of the reserve ratio.

货币乘数表示从既定的基础货币中可以创造出多少广义货币。在准备金率固定的简单模型中，乘数是准备金率的倒数。

m = 1 ÷ reserve ratio

m = 1 ÷ 准备金率

The money supply is then given by:

货币供应量则由下式给出：

M = H × m

In practice, the multiplier is smaller than the simple reciprocal because households hold cash outside banks and banks keep excess reserves. These leakages reduce the amount of deposits that can be re-lent, so the actual money supply rises by less than the theoretical maximum.

在实际中，乘数会小于简单的倒数，因为家庭持有银行体系之外的现金，银行也保留超额准备金。这些漏出减少了可再贷出的存款数量，因此实际货币供应的增长小于理论最大值。

---

6. Government Borrowing and the Banking System | 政府借款与银行体系

When a government runs a budget deficit, it borrows by issuing bonds. If the bonds are bought by commercial banks or the central bank, the transaction can increase the money supply.

当政府出现预算赤字时，它通过发行债券借款。如果债券由商业银行或中央银行购买，这笔交易可能会增加货币供应。

If the central bank purchases government bonds directly, this is called monetising the deficit. The central bank credits the government’s account with newly created reserves, which increases the monetary base and can support further credit creation.

如果中央银行直接购买政府债券，这被称为赤字货币化。中央银行将新创造的准备金记入政府账户，这会增加基础货币，并可能支持进一步的信用创造。

If commercial banks buy government bonds, their reserves fall initially, but later lending may be affected. The overall impact depends on whether the central bank accommodates the borrowing by supplying additional reserves through open market operations.

如果商业银行购买政府债券，其准备金起初会减少，但后来的贷款可能受到影响。总体影响取决于中央银行是否通过公开市场操作提供额外准备金来配合借款。

---

7. External Sources: Balance of Payments Inflows | 外部来源：国际收支流入

Money supply can also increase from abroad. A current account surplus means the economy earns more foreign currency than it spends, and when exporters convert foreign currency into domestic currency, bank deposits rise.

货币供应也可能来自国外。经常账户顺差意味着经济体赚取的外汇多于支出，当出口商将外汇兑换为本币时，银行存款会增加。

Capital inflows, such as foreign direct investment or portfolio investment, also

Published by TutorHao | A-Level Economics Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）