Cambridge O Level Economics: Money, banking and household spending, saving and borrowing (2281)

This guide follows the Cambridge O Level Economics 2281 syllabus for examination in 2026. It covers sections 3.1.1 (money), 3.1.2 (banking) and 3.2.1 (influences on spending, saving and borrowing), all from topic 3, Microeconomic decision makers. The syllabus is not tiered, so everything here is for every candidate. Return to the Cambridge O Level Economics hub or tick items off on the printable checklist. For fast recall use the revision notes, then test yourself with the practice set. The wider topic is in the Microeconomic decision makers guide.

All countries, firms, households and figures below are invented for illustration. They are not real statistics.

What you must be able to do

Section	Official focus	You should be able to
3.1.1	Forms, functions and characteristics of money	Describe types of money, explain what money does, judge whether an item makes good money
3.1.2	Role and importance of central banks and commercial banks for government, producers and consumers	Explain what each type of bank does and why each matters to each of the three groups
3.2.1	Influences on spending, saving and borrowing: income, the rate of interest, confidence, between households and over time	Explain each influence, compare households, and explain changes for one household over time

3.1.1 Money

Why money exists

Under barter, people swap goods directly. Barter needs a double coincidence of wants: a baker who wants shoes must find a shoemaker who wants bread, at the same time. Goods may not divide (half a cow), may not keep, and every pair of goods needs its own exchange rate.

Worked example (invented). In a barter village with 5 goods, each pair of goods needs a rate: 5 × 4 ÷ 2 = 10 rates. With 50 goods: 50 × 49 ÷ 2 = 1,225 rates. If every good is priced in one money, 50 goods need only 50 prices. This is why money saves time and makes comparison easy.

Forms of money

• Commodity money: items valued for their own use, such as salt or cattle, used historically. Often poor at dividing and carrying.
• Coins and notes (cash): issued by the state or its central bank. Notes are paper or plastic and are not worth much as materials; people accept them because the issuer is trusted and the law accepts them for debts.
• Bank deposits: balances in accounts that can be moved by card, transfer or cheque. In many economies they are used for most large payments.
• Electronic and mobile money: balances moved by phone or online. The money is still a bank balance. Only the way it moves is new.

Functions of money

Function	Meaning	Example
Medium of exchange	Accepted in payment for goods and services	A worker is paid in money, then buys food
Unit of account	Prices, wages and debts are measured in it	A shirt costs 20 units, a haircut 8 units, so a shirt costs 2.5 haircuts
Store of value	Keeps purchasing power until used later	Saving 100 units this year to spend next year
Standard of deferred payment	Debts can be set now and repaid later	A loan of 800 units is agreed today and repaid with interest in a year

Characteristics of good money

Items are more useful as money if they are:

• acceptable: widely trusted, so people will take them
• durable: lasting through repeated use
• portable: easy to carry and transfer
• divisible: can pay for small and large items, and give change
• uniform: each unit is the same, so none is worth more than another
• limited in supply: if anyone can make it easily, it loses value
• stable in value: keeps its purchasing power fairly well

Worked example: store of value under inflation (invented). In Country A the price index goes up from 100 to 125. A unit of money now buys 100 ÷ 125 = 0.8, or 80 per cent, of what it bought. Prices rose by 25 per cent, but money lost 20 per cent of its purchasing power. Rising prices weaken money as a store of value, and if prices rise fast enough people lose trust in it as a medium of exchange.

Judging an item. Salt is durable and fairly uniform, but is heavy to carry in bulk and hard to divide exactly. A bank balance is divisible, portable and easy to transfer, but depends on trust in the bank and in the currency.

3.1.2 Banking

Central banks

A central bank is the main monetary authority of a country. It does not usually serve ordinary households. Typical roles:

• issues notes and coins
• acts as banker to the government, holding its accounts and handling payments and borrowing
• acts as banker to the commercial banks, holding their reserve balances and settling payments between them
• acts as lender of last resort, supporting a sound bank that runs short of cash so panic does not spread
• carries out the government’s monetary policy, mainly through the interest rate
• supervises banks and manages foreign currency reserves

Commercial banks

Commercial banks are private, profit-seeking firms used by the public. Typical roles:

• accept deposits and keep savings safe
• lend through loans, mortgages and overdrafts
• provide payment services: accounts, cards, transfers, cheques
• exchange currencies and offer advice and other services

Banks earn by charging borrowers more than they pay depositors.

Worked example (invented). A small bank holds deposits of 1,000,000 units and lends 80 per cent of them. Lent: 800,000. It charges 9 per cent on loans: 72,000 interest income. It pays 3 per cent to depositors: 30,000 cost. Gross interest margin: 72,000 − 30,000 = 42,000, before wages and other running costs. If it lent all deposits it would have nothing in hand for withdrawals, so banks keep part back.

Why banks matter to each group

Group	Central bank	Commercial banks
Government	Manages its accounts and borrowing; carries out its monetary policy; advises on money matters	Lend to it by buying its debt; collect and move tax and benefit payments
Producers	Keeps the payments system working and helps keep prices steady, which makes planning easier	Loans for equipment and expansion, overdrafts for short gaps, accounts for wages and supplier payments
Consumers (households)	Protects deposits by supporting the banking system; keeps the currency trusted	Safe savings, mortgages and loans, cards, everyday payments

Evaluation chain. Bank lending lets firms invest and households buy homes, which can raise output. But if banks lend carelessly and many borrowers default, banks make losses, may cut lending, and firms and households suffer. That is why central banks supervise banks and act as lender of last resort. The importance of the central bank depends on how much the public trusts the banking system and the currency.

3.2.1 Spending, saving and borrowing

A household’s disposable income (income after tax and deductions) is spent, saved or used to repay debt. Saving is income not spent. Borrowing brings spending forward, to be repaid from future income.

Income

Higher income allows more spending and more saving. Richer households usually save a larger share, since essentials take most of a low income.

Worked example (invented). Household A has disposable income of 3,000 a month, spends 2,550 and saves 450: saving ratio 450 ÷ 3,000 = 15 per cent. Household B has 1,200, spends 1,176 and saves 24: 24 ÷ 1,200 = 2 per cent. Household B must also borrow sooner if a bill is unexpected.

Income change over time. A household’s income rises from 2,000 to 2,400 (up 20 per cent). Spending rises from 1,700 to 1,980 (up 280 ÷ 1,700 = 16.5 per cent). Saving moves from 300 to 420, up 40 per cent. Of the extra 400, 280 (70 per cent) was spent and 120 saved. The saving ratio rose from 15 to 17.5 per cent.

The rate of interest

For savers, interest is a reward for not spending. For borrowers, it is the cost of borrowing.

Worked example: saving (invented). On 5,000 units, a rate of 2 per cent gives 100 a year and 4 per cent gives 200. The higher rate raises the reward for saving, though many households save for goals (a house, retirement) whatever the rate.

Simple and compound interest. On 2,000 units at 4 per cent for 3 years, simple interest is 2,000 × 0.04 × 3 = 240. With compound interest, 2,000 × 1.04³ = 2,249.73, so the interest is 249.73, which is 9.73 more because interest earns interest.

Worked example: borrowing (invented flat-rate loan). Borrow 12,000 for 2 years, repaid in 24 equal monthly instalments. At 8 per cent a year: interest 12,000 × 0.08 × 2 = 1,920; total 13,920; instalment 13,920 ÷ 24 = 580. At 10 per cent: interest 2,400; total 14,400; instalment 600. The rise of 20 a month is 3.45 per cent, and total repayment rises by 480.

Real interest. The real rate is roughly the nominal rate minus inflation. At 5 per cent interest and 3 per cent inflation, the real return is about 2 per cent. At 3 per cent interest and 4 per cent inflation it is about −1 per cent, so savings lose purchasing power.

Confidence

Confidence is how secure households feel about jobs, future income and prices. When it is high, households spend more, borrow for big purchases and save less. When it is low, they save a precaution fund, delay purchases and avoid new debt, even if current income has not changed.

Worked example (invented). Planned spending on non-essentials is 1,500 a month. Fear of job losses cuts it by 8 per cent: 1,500 × 0.92 = 1,380, so 120 a month moves to saving.

Between households and over time

Comparison	Influences
Between households	Income level, number of dependants, wealth, existing debts, attitudes to risk, access to credit, age
Over time (one household)	Stage of life (young adults borrow to study or buy a home, middle-aged households repay, older households run down savings), changes in income, interest rates, and confidence

Evaluation chain. Lower interest rates cut the cost of borrowing and the reward for saving, which should raise spending. The effect is smaller if confidence is low, if households already have heavy debt, or if lenders will not lend. So income, interest and confidence interact, and you should say which matters most in the situation given.

Common errors

• Describing money as “cash only”. Bank deposits are money too.
• Listing functions without explaining them. Give an example of each.
• Confusing a central bank with a large commercial bank.
• Saying a rate rise always cuts spending. Say how strongly, and what else matters.
• Treating saving and borrowing as opposites for every household. Many do both.
• Mixing up the saving ratio (a share of income) with the amount saved: in the example, Household A saves 450 at 15 per cent and B saves 24 at 2 per cent, so say which one you are using.

For practice questions with worked answers use the practice set, take a free 10-minute diagnostic, and see the past papers page. Both papers allow calculators, according to the assessment overview.

Official syllabus

Cambridge O Level Economics 2281, syllabus for examination in 2026, version 2, published by Cambridge University Press and Assessment (Cambridge International). Sections 3.1.1, 3.1.2 and 3.2.1.