A Level Economics: Basic Economic Ideas and Resource Allocation — Revision Notes

Condensed for the final weeks. For the full explanation, use the Basic Economic Ideas and Resource Allocation study guide.

The fundamental problem

Scarcity — resources are finite while wants are infinite. Everything else in economics follows from this.

Three questions every economy must answer: what to produce, how to produce it, and for whom.

Opportunity cost — the value of the next best alternative forgone. Not “what you lose” in general, and not the sum of all alternatives. The word next is what earns the mark.

Factors of production: land (natural resources, earns rent), labour (human effort, wages), capital (man-made aids to production, interest), enterprise (risk-taking and organisation, profit).

Production possibility curves

A PPC shows the maximum combinations of two goods with all resources fully and efficiently employed.

Position	Meaning
On the curve	Productively efficient, full employment
Inside the curve	Unemployment or inefficiency
Outside the curve	Currently unattainable

The curve is concave to the origin because opportunity cost increases — resources are not perfectly substitutable, so as more of one good is made, increasingly unsuitable resources must be switched, and more of the other good is sacrificed each time.

• Movement along the curve = a reallocation of existing resources, incurring opportunity cost.
• Outward shift = economic growth: more resources, better technology, improved education or productivity.

Choosing capital goods over consumer goods today shifts the PPC further out in future — the classic present-versus-future trade-off.

Positive and normative

Positive statements are factual and can be tested against evidence. Normative statements contain a value judgement and involve words like should, ought, fair, too much.

“Unemployment rose to 8%” is positive. “The government should reduce unemployment” is normative. A statement can be positive and still be wrong — testability, not truth, is the criterion.

The price mechanism

Prices perform three functions, and naming all three is usually worth three marks:

1. Signalling — prices convey information about relative scarcity to buyers and sellers.
2. Incentive — a higher price encourages producers to supply more and consumers to buy less.
3. Rationing — a higher price allocates scarce goods to those willing and able to pay.

Adam Smith’s “invisible hand” is the idea that self-interested action, coordinated by prices, allocates resources without central direction.

Economic systems

System	Allocation	Strength	Weakness
Market	Price mechanism	Efficiency, choice, innovation	Inequality, market failure, no public goods
Planned	Government	Equity, provision of merit and public goods	Inefficiency, no incentive, poor information
Mixed	Both	Balances the two	Requires effective regulation

Almost every real economy is mixed; the exam question is usually about the degree of intervention, not a binary choice.

Market failure

Where the free market fails to allocate resources efficiently.

Type	Explanation
Negative externality	Cost to a third party — social cost exceeds private cost, so the good is over-produced
Positive externality	Benefit to a third party — social benefit exceeds private benefit, so the good is under-produced
Public goods	Non-excludable and non-rival — the free-rider problem means the market provides none
Merit goods	Under-consumed because benefits are underestimated and there are positive externalities
Demerit goods	Over-consumed because harms are underestimated
Information failure	Consumers cannot judge value accurately
Monopoly power	Output restricted, price raised above the competitive level

Public goods must be defined by both properties. Non-excludable means non-payers cannot be prevented from consuming; non-rival means one person’s consumption does not reduce the amount available to others. Street lighting and national defence are the standard examples. Because of free riding, no private firm can profitably supply them — this is the strongest argument for government provision.

Government failure occurs when intervention creates a worse outcome than the market — through information gaps, administrative cost, unintended consequences such as black markets, or regulatory capture. A top-band answer always considers it.

Exam traps

• Defining opportunity cost without “next best”.
• Explaining the concave PPC as “the law of diminishing returns” instead of imperfect resource substitutability.
• Giving only one property of a public good.
• Confusing merit goods with public goods — merit goods can be, and are, sold privately.
• Judging a positive statement by whether it is true rather than whether it is testable.
• Presenting intervention as automatically improving on the market.

Self-test

1. Define opportunity cost precisely.
2. Why is a PPC concave to the origin?
3. State the three functions of the price mechanism.
4. Give both defining properties of a public good and explain the free-rider problem.
5. What distinguishes a positive from a normative statement?

Answers: 1. The value of the next best alternative forgone. 2. Resources are not perfectly substitutable between uses, so as output of one good rises, increasingly unsuitable resources must be transferred and the opportunity cost rises. 3. Signalling, incentive and rationing. 4. Non-excludable and non-rival; because non-payers cannot be excluded, consumers have an incentive to free-ride, so no private firm can cover its costs and the market provides none. 5. A positive statement is factual and testable against evidence; a normative statement contains a value judgement and cannot be tested.