Total and marginal utility, diminishing marginal utility, and the rational consumer the model has to assume in order to work.
Why is the third drink never as good as the first?
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 | 4.1.2.1 | Consumer behaviour |
| Edexcel A Economics 9EC0 | 1.2.1 | Theme 1 |
| Pearson Edexcel IAL Economics | WEC11 · Unit 1 | Markets in action |
Total and marginal utility, diminishing marginal utility, and the rational consumer the model has to assume in order to work.
AQA sets this out as 4.1.2.1 — Consumer behaviour, inside Individual economic decision making. Utility, imperfect information, and why real people behave badly. It is assessed on Paper 1 and Paper 3.
Topic pages on this site are not written and abandoned. Each one gets the definition and the specification framing first, then the diagram drawn properly, then how the board actually examines it, and then the five branches below — added over months rather than dumped in one go.
This page is at the first stage. If you need 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.
All-you-can-eat pricing works because the restaurant knows your marginal utility falls faster than your appetite suggests.
Streaming replaced buying albums because access to everything is worth more than ownership of ten things.
Buffet queues and loyalty cards are both bets about where your marginal utility goes next.
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 apply and test a model topic, so here is what each objective looks like on it specifically.
| Weight | What it is | What it means on utility theory | |
|---|---|---|---|
| AO1 | 20–23% | Knowledge and understanding of terms, concepts, theories and models | State the model and, where it has one, the name attached to it. Named theory is credited. |
| AO2 | 26–29% | Application of that knowledge to economic contexts | Apply it to a real agent — a named firm, market or household — and let the specific detail carry the application. |
| AO3 | 26–29% | Analysis of issues and their impact on economic agents | Follow the logic to a prediction the model actually makes, not to the conclusion you wanted. |
| AO4 | 22–25% | Evaluation of arguments, using evidence to support a judgement | Test the model against the evidence. This is a topic where the model has been revised by events, and knowing that is the evaluation. |
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.
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