Scarcity and the need to choose
Economics starts from one problem that every society shares.
People's wants have no natural limit, but the resources that could satisfy them are limited.
This gap is scarcity, and Cambridge treats it as the fundamental economic problem.
Every other topic in the course, from elasticity to exchange rates, is a study of how people, firms and governments cope with it.
You met scarcity at IGCSE.
At AS Level you need to state it precisely, explain why it never goes away, and use it as the first link in a chain of reasoning about choice and cost.
Why wants are unlimited and resources are limited
Wants are unlimited for two reasons.
First, there are a great many of them: food, housing, health care, travel, entertainment, security and status.
Second, they grow as they are met.
A household that buys its first car soon wants a second, or a better one.
Rising income changes the list; it does not shorten it.
Resources are limited because the factors of production (land, labour, capital and enterprise, section 6) exist in fixed amounts at any moment.
A country has a given area of farmland, a given number of workers with given skills, and a given stock of machines.
Technology and investment can add to these over time, but never without limit and never instantly.
Scarcity is therefore relative, not absolute.
A good is scarce when the amount people want at a zero price is greater than the amount available.
Very rich countries face scarcity as surely as poor ones: Norway or Singapore still cannot provide every hospital, school and road their citizens would like.
A shortage is a market situation in which quantity demanded exceeds quantity supplied at the current price (unit 2), and it can disappear when the price rises.
Scarcity is permanent: it would remain even if every market were in equilibrium.
From scarcity to choice
Because resources cannot satisfy every want, they must be allocated: someone has to decide which wants are met and which are not.
That decision is a choice, and scarcity forces it at every level of the economy.
Decision-maker
Scarce resources
Typical choice
Individual or household
Income, time, skills
Spend or save; study or take a paid job; which goods to buy
Firm
Capital, workers, land, the owner's time and funds
What to produce; which method to use; whether to expand
Government
Tax revenue, borrowing capacity, public land, civil servants
Health or defence; build roads or schools; cut taxes or raise spending
The chain is always the same: scarcity → choice → a cost of that choice (section 2 calls that cost opportunity cost).
Strong answers state each link.
Weak answers jump from "resources are scarce" straight to "so the government must cut spending", leaving the reader to guess why.
The margin: how choices are actually made
Most real choices are not "all or nothing".
A student does not choose between studying and never sleeping; she chooses whether to study one more hour.
A firm decides whether to make one more batch.
A government decides whether to add one more hospital to its plan.
Economists call this choosing at the margin, and Cambridge names "the margin and decision-making" as a key concept of this topic.
A rational decision-maker carries on with an activity while the extra benefit of one more unit is greater than its extra cost, and stops when the two are equal.
You will use this rule later in the course (a firm producing where the extra revenue from one more unit equals its extra cost).
For now, notice that the margin is just scarcity applied one unit at a time: the extra hour spent revising is an hour not spent working or resting.
Choices are not always made on marginal reasoning alone.
People and governments also weigh facts, theory, priorities and values.
A government may build a rural clinic that costs more per patient than an urban one, because it judges that fair access matters.
That is still a choice under scarcity: it simply rests partly on a value judgement (section 4).
- Scarcity: the situation in which unlimited wants exceed the limited resources available to satisfy them, so not every want can be met.
- Fundamental economic problem: the problem of allocating scarce resources between competing uses, which every economy faces because wants exceed resources.
- Choice: the decision about which wants to satisfy with scarce resources, which must be made by individuals, firms and governments.
- Margin: the next (one extra) unit of an activity; a decision at the margin compares the extra benefit with the extra cost of that unit.
Explain why a government that receives a large rise in tax revenue still faces the fundamental economic problem. [Analyse] [4]
Top answer. The fundamental economic problem is that wants are unlimited while resources are limited (1).
The extra revenue lets the government buy more resources, but the total is still finite: there are only so many doctors, teachers and building firms in the economy at any time (1).
Meanwhile citizens' wants for public services grow, for example as the population ages and expects better health care (1).
So the government still cannot meet every request and must choose which projects to fund and which to delay (1).
Weaker answer. "The government still has to make choices because it cannot afford everything."
This is true but it is an assertion: it never says why resources stay limited or why wants keep growing, so it earns 1 or 2 of the 4 marks.
The missing links are the fixed supply of real resources and the growth of wants.
Outcome: a 4-mark explain needs four linked steps that end on the variable in the question (here, the need to choose).
A town has one sports ground. Explain how scarcity affects choices made by a household, a firm and the town council about this ground. [Apply] [4]
1. Household: a family has two free hours on Saturday. If they spend them watching a match, they cannot spend them shopping or working extra hours (1).
2. Firm: a sports club that rents the ground must choose how many hours to book for training and how many for paying events, since it has only so much money to spend on rent (1).
3. Council: the ground could host football or a weekly market, but not both at once. The land is the scarce resource, so the council must pick one use (1).
4. In each case a limited resource (time, money, land) meets competing wants, so a choice is unavoidable (1).
Outcome: each point names the scarce resource, the competing uses, and the choice.
The final line ties all three back to scarcity.
Begin any answer on scarcity with the full definition, both halves of it: unlimited wants and limited resources.
Then use it.
Examiners reward a definition only when the answer goes on to apply it to the case in the question, so follow it at once with the specific resource that is scarce and the specific choice it forces.
- Saying scarcity means "a shortage of something". A shortage is temporary and caused by a price below equilibrium; scarcity is permanent and applies even to plentiful goods.
- Claiming a rich country, or a firm making large profits, does not face scarcity. Resources are always finite relative to wants.
- Writing "people cannot afford it" as the reason for scarcity. Affordability is about income and price; scarcity is about real resources against wants.
- Missing a trap word. "Explain why all economies face scarcity" wants a reason that applies to rich and poor alike; an answer about poverty in low-income countries answers a different question.
Check your understanding
1. Which statement best explains why choice is at the heart of the economic problem? [Recall] [1] A Firms are unable to produce goods that consumers want. B Governments set prices below their equilibrium level. C Prices rise whenever demand rises. D Resources are limited relative to the wants they could satisfy.
2. A country discovers a large new oil field. What is the most likely effect on the fundamental economic problem? [Apply] [1] A It disappears, because the country can now satisfy all wants. B It remains, because wants still exceed the resources available. C It remains only for households, because the government now has enough revenue. D It turns into a shortage that a price rise will remove.
3. Table 1.1 shows the extra benefit and the extra cost to a student of each hour of revision on one evening. How many hours should she revise to make her net gain as large as possible? [Analyse] [1]
Table 1.1 Extra benefit and extra cost of each hour of revision (in points of value)
Hour
1st
2nd
3rd
4th
5th
Extra benefit
50
40
30
20
10
Extra cost
10
15
20
25
30
A 2 B 3 C 4 D 5
4. Define scarcity. [Recall] [2]
5. A university library has 200 study desks. In exam season 350 students want one each afternoon. Explain, using the information, how the library faces the fundamental economic problem. [Apply] [2]
6. Explain why scarcity forces a firm to make choices, and why it still does so after its profits double. [Analyse] [4]
7. Explain what is meant by a decision at the margin, using the example of a student deciding how long to revise. [Analyse] [4]
8. Assess whether economic growth can ever solve the problem of scarcity. [Evaluate] [6]
Answers
1. D (1). Limited resources against wants means not every want can be met, so a choice must be made.
- A: true of some firms but not the reason choice is central (true but not the asked thing).
- B: describes a price control, which causes a shortage, not scarcity (partner term: shortage for scarcity).
- C: a statement about markets, unrelated to why choice is needed.
2. B (1). The oil field adds resources, but wants grow and remain unlimited.
- A: confuses more resources with unlimited resources.
- C: the government still faces competing demands for its revenue.
- D: scarcity is not a shortage; no price change removes it.
3. B (1). Keep going while an hour's extra benefit is greater than its extra cost. The 3rd hour adds 30 for a cost of 20; the 4th adds 20 for a cost of 25. Net gain after 3 hours is , against after 4.
- A: stops while the 3rd hour still adds more benefit (30) than cost (20).
- C: compares the 4th hour's benefit with the 1st hour's cost, as if extra cost stayed fixed.
- D: counts every hour that adds any benefit and ignores the cost (total benefit taken for net gain).
4. A situation in which wants are unlimited (1) but the resources to satisfy them are limited, so not all wants can be met (1).
5. The desks are the limited resource: only 200 are available (1). Wants exceed them by 150 students, so the library must choose how to allocate desks, for example by booking or first come, first served (1).
6. Max 4. The firm's resources (workers, machines, funds, managers' time) are limited (1) while the uses it could put them to are many: new products, new markets, higher pay, research (1). So it must choose which uses to fund and give up the others (1). Doubling profits raises its funds but they are still finite, and its ambitions grow with them, so it still cannot do everything (1).
7. Max 4. A decision at the margin is about one extra unit of an activity (1), comparing the extra benefit of that unit with its extra cost (1). For the student: one more hour of revision may add a few marks (benefit) but costs an hour of sleep, rest or paid work (1). She should keep revising while the extra benefit exceeds the extra cost, and stop when they are equal; as she tires, extra hours add less (1).
8. Up to 3 for why growth eases scarcity: more output means more wants can be met (1); higher incomes can fund public services (1); new technology lets the same resources produce more (1). Up to 3 for why it cannot solve it: wants grow with income, so new wants replace those met (1); growth uses finite natural resources such as minerals and clean air (1); some goods, such as land in city centres, cannot be increased (1). Up to 2 for evaluation: weighs the two sides, for example growth reduces the severity of scarcity for basic needs but not its existence (1). Reserve 1 for a justified conclusion that answers "ever": growth can never solve scarcity because wants are unlimited by nature (1). Accept any valid example of a resource or a want.