Injections, withdrawals, equilibrium, and why the model is the skeleton the whole of macro hangs on.
Where does money actually go when you spend it?
The economics does not change between boards — only the reference number and the exam style. This page is written to the concept, so find your own line below and read on.
| Specification | Reference | Section |
|---|---|---|
| AQA A-Level Economics 7136 | 4.2.2.1 | The circular flow of income |
| Edexcel A Economics 9EC0 | 2.2.1 | Theme 2 |
| Pearson Edexcel IAL Economics | WEC12 · Unit 2 | Macroeconomic performance and policy |
Injections, withdrawals, equilibrium, and why the model is the skeleton the whole of macro hangs on.
AQA sets this out as 4.2.2.1 — The circular flow of income, inside How the macroeconomy works. Circular flow, AD and AS, and the multiplier. It is assessed on Paper 2 and Paper 3.
Equilibrium national income is where total injections equal total withdrawals (J = W). Raise J relative to W and Y rises through the multiplier; raise W relative to J and Y falls. [AO1 · AO3]
Topic pages on this site are not written and abandoned. The definition and specification framing came first. The diagram above and the full sourced model answer in Section IV below have now been brought forward and published. The deeper application in Section II, the misconception film, and the examiner's line are still being added over the months ahead — rather than dumped in one go.
If you need the rest of this topic before then, the revision platform already covers the full specification interactively, and the Intelligence Briefing carries model answers on the essays most likely to appear.
Application is worth more marks than knowledge on this specification — AO2 carries 26–29% against AO1's 20–23%. So the examples are not decoration. They are where a third of the paper lives, and the ones that earn are the ones specific enough to be checked.
Injections and withdrawals decide whether national income rises, falls or sits still.
Saving is a withdrawal, which is why a nation deciding to be prudent at once can shrink itself.
Every macro model in the specification is this diagram with more detail added.
Each of these becomes a full piece in its own right, in the branches below. What is here is the hook; the argument, the data and the essay application are what the pieces are for.
Every question on this specification is marked against four assessment objectives, and they are not weighted equally. Most revision treats a topic as a body of knowledge; the paper treats it as four separate skills applied to that knowledge. This topic is examined as a draw and explain topic, so here is what each objective looks like on it specifically.
| Weight | What it is | What it means on the circular flow of income | |
|---|---|---|---|
| AO1 | 20–23% | Knowledge and understanding of terms, concepts, theories and models | Draw it with both axes labelled and every curve named. The marks are for the labels, not for the neatness. |
| AO2 | 26–29% | Application of that knowledge to economic contexts | Put the context onto the diagram — the named market, the actual price, the direction the question is asking about. |
| AO3 | 26–29% | Analysis of issues and their impact on economic agents | Explain the movement as a sequence: what shifted, what that did, what followed. Chains earn marks; assertions do not. |
| AO4 | 22–25% | Evaluation of arguments, using evidence to support a judgement | Question your own diagram. The elasticities you drew, the time period you assumed, and whether the curve should shift or the point should move. |
A full worked question on this spec point, in the board's own register: the practice question and both mark-scheme plans are below for everyone. The full sourced model answer, AO-tagged against real examiner weightings, unlocks by email — the same way the Intelligence Briefing's predicted essays do.
Explain how a rise in the UK household saving ratio could affect the equilibrium level of national income.
Everything above is the anchor. The pieces below take it further, and each one is built to train a particular assessment objective rather than to cover the topic again. They accumulate — nothing on this page gets deleted, it gets added to.
The revision platform covers the whole specification now, and the Academy marks your written answers against the framework examiners use. The library is the free layer, not the only one.
Enquire about a place See the platform