Economic methodology is the set of tools, techniques and procedures that economists use to develop, test and apply theories about how societies allocate scarce resources to satisfy unlimited wants. As a social science, economics must deal with:
Positive statements describe the world as it is – they are testable and fact‑based. Normative statements prescribe how the world ought to be – they contain value‑laden judgements.
| Aspect | Positive Economics | Normative Economics |
|---|---|---|
| Purpose | Explain “what is”. | Advise “what ought to be”. |
| Language | Fact‑based, testable. | Value‑laden (good, bad, fair, just). |
| Example | “A £10 increase in the minimum wage raises the equilibrium wage for low‑skill workers.” | “The government should raise the minimum wage to reduce income inequality.” |
| Methodology | Empirical testing, statistical inference. | Ethical reasoning, welfare analysis. |
The ceteris‑paribus assumption isolates the effect of one variable by holding all other relevant factors constant. It is essential for:
Example: When analysing the impact of a price rise on the quantity demanded of coffee, we hold income, tastes and the price of tea constant.
Link to the rest of the syllabus: Ceteris‑paribus is used throughout micro‑ and macro‑analysis – demand‑supply curves, elasticity calculations, AD/AS shifts, and the analysis of fiscal and monetary policy.
Economic models are simplified representations of reality. They rely on explicit assumptions that make analysis possible but also limit applicability. Students must be able to identify the key assumptions for each major model and critique them.
| Model | Core Assumptions | Typical Limitation |
|---|---|---|
| Perfect Competition | Many buyers & sellers, homogeneous product, perfect information, free entry/exit, price‑taking behaviour | Real markets often have product differentiation, information asymmetry or barriers to entry. |
| Demand‑Supply (Micro) | Rational consumers/producers, ceteris‑paribus, markets clear | Ignores behavioural biases and short‑run rigidities. |
| Aggregate Demand‑Aggregate Supply (AD/AS) | Price level is the only variable affecting real output in the short run, expectations are stable | Expectations can shift rapidly; supply shocks may be ignored. |
| Keynesian Cross (Expenditure‑output model) | Planned expenditure determines actual output, no price adjustments in the short run | In reality, prices do adjust and can affect demand. |
| Approach | Typical Tools & Cambridge‑style Example |
|---|---|
| Positivism (Positive Economics) | Deductive reasoning, mathematical modelling, statistical testing. Example: estimating the price elasticity of demand for smartphones using regression analysis. |
| Interpretivism (Qualitative/Interpretive Economics) | Interviews, case studies, content analysis. Example: interviewing shoppers to explore why they choose organic produce despite higher prices. |
| Critical Realism | Combines quantitative analysis with a critique of power structures. Example: analysing how a progressive tax system affects income distribution and social equity. |
Y_t = α + β G_t + ε_t| Step | Positive analysis | Normative judgement |
|---|---|---|
| 1. Identify the policy | Introduce a carbon tax of £20 per tonne of CO₂. | Goal: reduce greenhouse‑gas emissions. |
| 2. Analyse impact (ceteris‑paribus) | Model predicts a 10 % fall in emissions and a 2 % rise in electricity prices. | Consider who bears the cost – households vs. firms. |
| 3. Evaluate | Positive result: emissions fall. | Normative question: Is the distributional impact fair? Should revenue be recycled to low‑income households? |
Making these value‑judgements explicit improves transparency and strengthens evaluation arguments.
Economics, as a social science, blends theoretical abstraction with empirical investigation while recognising the inevitable role of values. Mastering the distinction between positive and normative statements, the ceteris‑paribus assumption, model assumptions and their limitations, and methodological pluralism equips students to analyse economic issues rigorously (AO1‑AO2) and to evaluate policies critically (AO3) – the core skills required for Cambridge International AS & A Level Economics.
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