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What is Economics?

Clear, syllabus-mapped IB Economics revision notes on what is economics? — explanations, worked examples and exam technique, then a free targeted practice drill.

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Syllabus points

The fundamental economic problem

Human wants are unlimited, but the resources available to satisfy them are limited. This mismatch is scarcity, and it is the starting point of the whole subject. Because resources are scarce, every individual, firm and government must choose how to use them — and every choice sacrifices the next best alternative.

Unlimited wants + limited resources → scarcity → choice → opportunity cost → resource allocation

Opportunity cost is the value of the next best alternative forgone when a choice is made. It applies to consumers (spend or save), firms (which product to make) and governments (hospitals or schools).

Key definitions

TermExam-ready definition
ScarcityLimited resources are insufficient to satisfy unlimited wants.
Opportunity costThe benefit of the next best alternative forgone when a choice is made.
Economic goodA good that is scarce and therefore has an opportunity cost.
Free goodA good with no opportunity cost because it is not scarce (e.g. sunlight).
Factors of productionThe inputs used to produce goods and services.

The factors of production

Economists group all resources into four factors, each earning a reward:

The three basic questions

Scarcity forces every economy to answer three questions:

  1. What to produce? Which goods and services, and in what quantities.
  2. How to produce? Which combination of factors and methods.
  3. For whom to produce? How output is distributed among people.

Different economic systems answer these differently. In a free-market system the price mechanism decides; in a planned system the government decides; a mixed economy (the real-world norm) combines both, with markets allocating most resources and government intervening where markets fail.

The production possibilities curve (PPC)

A PPC shows the maximum combinations of two goods an economy can produce when all resources are used fully and efficiently. Picture two axes — say capital goods and consumer goods — joined by a curve bowing outwards from the origin.

Worked example

An economy moves resources from producing consumer goods towards capital goods (machines, infrastructure). In the short run, current consumption falls. In the long run, the extra capital raises productive capacity, so the PPC shifts outward and more of *both* goods becomes possible. The opportunity cost of higher future growth is lower consumption today.

Common exam mistakes

Exam technique

Define the term precisely (AO1), then build the chain of reasoning (AO2): scarcity → choice → a specific opportunity cost in the context given. Use the PPC to *illustrate* trade-offs and growth rather than just describing it.

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