IB Economics SL Aggregate Demand and Aggregate Supply: Diagrams, Shifts, and Evaluation

This revision guide turns AD + AS into an exam-ready map for IB Economics SL. It focuses on the definitions, diagrams, calculations, and explanation moves that usually separate a vague answer from a mark-worthy one.

Quick Answer

Learn the core language first: aggregate demand, aggregate supply, macroeconomics. Then connect it to the visual method: AD components, SRAS + LRAS, Shifts, Evaluation. In the exam, your answer should move through: define macro terms, draw diagram, explain shifts, evaluate policy.

Core Concept That Gets Marks

The main idea is not to memorise isolated notes. Treat AD + AS as a linked system: AD components gives the starting terms, SRAS + LRAS builds the method, Shifts provides the diagram or calculation, and Evaluation turns it into exam wording.

Visual Route

Use the study board below as the article's visual route. Each block is deliberately tied to the exam chain, so the image is not just decorative: it tells you what to define, what to draw, what to calculate or compare, and how to finish the explanation.

Weak Answer vs Mark-Worthy Answer

How To Build The Answer

1. Define macro terms: connect it to AD components.
2. Draw diagram: connect it to SRAS + LRAS.
3. Explain shifts: connect it to Shifts.
4. Evaluate policy: connect it to Evaluation.

Worked Exam Move

When the question asks about aggregate demand, write one exact definition, add a labelled diagram or calculation if relevant, and then use the question context. Avoid simply listing aggregate supply, macroeconomics, inflation; the examiner needs to see why each point matters.

Common Mistakes

• Confusing aggregate demand with a related term or using it without context.
• Confusing aggregate supply with a related term or using it without context.
• Confusing macroeconomics with a related term or using it without context.
• Confusing inflation with a related term or using it without context.

Mini Checklist

• Key terms are defined.
• Diagram labels are readable.
• Data, arrows, equations, or examples are used.
• The final sentence answers the command word directly.

FAQ

What should I revise first for AD + AS? Start with AD components and SRAS + LRAS, because they give you the vocabulary and method.

How should I use diagrams? Draw only the parts that answer the question, but label them carefully. For this topic, useful visuals include AD-AS macro diagram, inflationary gap, recessionary gap.

What makes the final answer stronger? Finish by using the command word: explain, compare, calculate, justify, or evaluate. The last sentence should make the mark scheme link obvious.

Related Revision Links

• More IB Economics revision guides
• Topic practice questions
• Mark scheme wording practice

Study Order For This Topic

Do not revise AD + AS as a flat list of notes. Start with AD components, because that gives you the language the question is likely to use. Then move to SRAS + LRAS, where most students need to show a method, diagram, calculation, or comparison. After that, use Shifts to practise applying the idea to a new context. Finish with Evaluation, because that is usually where the explanation mark or final method mark appears.

This order matters for IB Economics because exam questions rarely reward recognition alone. The answer has to show that you can move from a term to a method, then from a method to an explanation. If you only memorise the first two words on the page, your answer may sound correct but still miss the markscheme link.

Command Word Plan

What The Image Is Checking

The cover and study-board image are not decoration. They lock the revision into a visual route: AD-AS macro diagram, inflationary gap, recessionary gap, and demand components. When you look at the image, ask whether you can explain each drawing in one sentence without reading the article. If you cannot, that is the part to practise before doing a timed question.

For the body study board, use the bottom exam chain as your marking checklist. Your answer should move through define macro terms, draw diagram, explain shifts, and evaluate policy. If one step is missing, the answer usually becomes a note rather than an exam response.

Practice Routine

Use this 25-minute routine before opening a full paper:

1. Spend five minutes rewriting the key terms: aggregate demand, aggregate supply, macroeconomics.
2. Spend five minutes redrawing one visual from the cover, such as AD-AS macro diagram or recessionary gap.
3. Spend seven minutes answering one short question using the chain: define macro terms, draw diagram, explain shifts, evaluate policy.
4. Spend five minutes marking only the missing wording, not the whole page.
5. Spend three minutes turning the correction into one flashcard or one error-log sentence.

This keeps revision active. The goal is not to make the notes longer; it is to make the next answer more precise.

Markscheme Language To Reuse

Strong answers usually contain three things: the exact term, the visible evidence, and the final consequence. For this topic, that means using words such as aggregate demand, aggregate supply, macroeconomics, and inflation in a sentence that actually answers the question. A weak answer often names the word but does not show what changes, what is measured, what is compared, or why the result matters.

Before you finish, read your last sentence. If it could fit almost any topic, rewrite it. The last sentence should clearly belong to AD + AS.