Nature and Scope of Economics
The Nature and Scope of Economics domain examines how economics is defined, divided and methodologically studied; the exam tests your ability to apply definitions and distinguish micro from macro and positive from normative reasoning.
Core rules and concepts
- Wealth definition: Adam Smith treated economics as the science of wealth; critics said it neglected welfare and distribution.
- Welfare definition: Alfred Marshall viewed economics as the study of material welfare.
- Scarcity definition: Lionel Robbins defined economics as the science of choice under scarce means with alternative uses.
- Microeconomics studies individual units such as a consumer or firm; macroeconomics studies aggregates such as national income and inflation.
- Positive economics explains what is; normative economics evaluates what ought to be.
- Every economy faces the central problems of what to produce, how to produce and for whom to produce.
Worked example
A farmer owns two hectares and can grow paddy or sugarcane. The land is scarce and has alternative uses. If paddy is chosen, the sugarcane output given up is the opportunity cost. The choice illustrates allocation and can be shown on a production possibility frontier: points on the curve are efficient, points inside show underuse, and points outside are unattainable with current resources.
Traps that cost marks
Do not call Robbins’ definition a welfare definition. Do not label a policy recommendation “positive”. Do not treat microeconomics as merely “small” topics: it concerns individual decision-making units. Remember that opportunity cost is the next best alternative forgone, not the sum of all alternatives.