Unit 3 · Unit 3: Macroeconomics
The Complete IB Economics Guide · IB EconomicsUnit 3 · Unit 3: Macroeconomics
- The Complete IB Economics Guide
- IB Economics
- 4 sections
International Baccalaureate does not publish a per-unit weighting for this exam. Exam structure (official): SL: External Assessment (70%) · Paper 1 (75 min, 30%) · Paper 2 (105 min, 40%) · Internal Assessment (30%); HL: External Assessment (285 min, 80%) · Paper 1 (75 min, 20%) · Paper 2 (105 min, 30%) · Paper 3 (105 min, 30%) · Internal Assessment (20%). Be ready to carry the same unit skills and representations into a complete answer on every paper. Gross domestic product measures the market value of final goods and services produced within an economy over a period. Nominal GDP uses current prices; real GDP removes price change with a base-year price structure. GDP per capita adjusts for population but not distribution or unpaid activity.
- How IB Economics assesses this International Baccalaureate publishes no per-unit percentage for IB Economics; Paper 1 accounts for 30% of the SL total and 20% of the HL total. · SL: External Assessment (70%) · Paper 1 (75 min, 30%) · Paper 2 (105 min, 40%) · Internal Assessment (30%) | HL: External Assessment (285 min, 80%) · Paper 1 (75 min, 20%) · Paper 2 (105 min, 30%) · Paper 3 (105 min, 30%) · Internal Assessment (20%) · show the model with a nominal and real GDP calculation table, an aggregate demand and short-run aggregate supply diagram, a policy transmission chain from action to economic objectives
- Key skills National Income Accounting and the Business Cycle, Aggregate Demand, Aggregate Supply, and Macroeconomic Equilibrium, Economic Growth and Unemployment, Inflation, Deflation, and Conflicts Between Macroeconomic Objectives, Economic Inequality and Poverty, Demand Management: Monetary and Fiscal Policy, Supply-Side Policies, The Keynesian Multiplier, the Money Market, and Sustainable Government Debt (HL)
- How to study for Unit 3 This page turns a nominal and real GDP calculation table, an aggregate demand and short-run aggregate supply diagram, a policy transmission chain from action to economic objectives into one route: Decide whether the prompt asks for a level, rate, index, real adjustment, curve shift, or policy transmission chain..
- The organizing decision Diagnose the measurement or shock before choosing a model, calculation, or policy response.
What IB Economics Unit 3 covers
Use this map to connect each assessed skill to the relationship or representation that makes it visible.
National Income Accounting and the Business Cycle
GDP deflator; potential output; spending multiplier02Aggregate Demand, Aggregate Supply, and Macroeconomic Equilibrium
GDP deflator; potential output; spending multiplier03Economic Growth and Unemployment
GDP deflator; potential output; spending multiplier04Inflation, Deflation, and Conflicts Between Macroeconomic Objectives
GDP deflator; potential output; spending multiplier05Economic Inequality and Poverty
GDP deflator; potential output; spending multiplier06Demand Management: Monetary and Fiscal Policy
GDP deflator; potential output; spending multiplier07Supply-Side Policies
GDP deflator; potential output; spending multiplier08The Keynesian Multiplier, the Money Market, and Sustainable Government Debt (HL)
GDP deflator; potential output; spending multiplierInternational Baccalaureate does not publish a per-unit weighting for this exam.
Official unit name and weighting: IB subject guide / subject brief.
Unit map: connect measurement, models, and policy
Connect the published share to the unit model
Gross domestic product measures the market value of final goods and services produced within an economy over a period. Nominal GDP uses current prices; real GDP removes price change with a base-year price structure. GDP per capita adjusts for population but not distribution or unpaid activity.
Aggregate demand is total planned expenditure at alternative price levels. Short-run aggregate supply reflects production costs and capacity constraints, while long-run productive capacity depends on resources, institutions, and technology. Shifts, not movements, must be tied to a determinant.
Calculation discipline matters because a correct formula can still answer the wrong question. Identify whether the task asks for a level, rate, index, or real adjustment; use observations from the same basis and period; delay rounding; then attach the unit and explain the result.
The decision that organizes this unit
Define the system and choose the route before calculating
Diagnose the measurement or shock before choosing a model, calculation, or policy response.
Decide whether the prompt asks for a level, rate, index, real adjustment, curve shift, or policy transmission chain.
Mechanism route and repair branches
Relationships to preserve
- Nominal GDP uses current prices, while real GDP uses a base-year price structure to separate output change from price change.
- A spending shock shifts aggregate demand, while a production condition shifts aggregate supply.
- Policy evaluation connects the instrument to behavior, the model, named objectives, and a conditional judgment.
Representations to read
- a nominal and real GDP calculation table
- an aggregate demand and short-run aggregate supply diagram
- a policy transmission chain from action to economic objectives
Branches to reject
- mistaking a nominal change for a real change
- drawing a curve shift without naming its determinant
- selecting a policy before diagnosing the shock
| Key concept | Why it's hard | What scores |
|---|---|---|
| Measurement | Nominal changes are mistaken for real changes. | Show the price adjustment and units. |
| AD–AS | A price-level movement is drawn as a curve shift. | Name the spending or cost determinant. |
| Policy | An instrument is named without a transmission chain. | Trace action → behavior → model → objectives. |
How IB Economics assesses Unit 3: Macroeconomics
What a complete response must make visible
Match the task to evidence that a reader can audit, then check the most likely reasoning failure before finalizing the response.
| Task | Evidence to show | Hurdle |
|---|---|---|
| National Income Accounting and the Business Cycle | GDP deflator; potential output; spending multiplier | mistaking a nominal change for a real change |
| Aggregate Demand, Aggregate Supply, and Macroeconomic Equilibrium | GDP deflator; potential output; spending multiplier | drawing a curve shift without naming its determinant |
| Economic Growth and Unemployment | GDP deflator; potential output; spending multiplier | selecting a policy before diagnosing the shock |
| Inflation, Deflation, and Conflicts Between Macroeconomic Objectives | GDP deflator; potential output; spending multiplier | mistaking a nominal change for a real change |
| Economic Inequality and Poverty | GDP deflator; potential output; spending multiplier | drawing a curve shift without naming its determinant |
| Demand Management: Monetary and Fiscal Policy | GDP deflator; potential output; spending multiplier | selecting a policy before diagnosing the shock |
| Supply-Side Policies | GDP deflator; potential output; spending multiplier | mistaking a nominal change for a real change |
| The Keynesian Multiplier, the Money Market, and Sustainable Government Debt (HL) | GDP deflator; potential output; spending multiplier | drawing a curve shift without naming its determinant |
Worked example: calculate real GDP and the deflator
Read each question as it appears on the exam paper, choose your answer, then tap it to see the feedback.
Practice 1: Separate nominal GDP from real GDP
A two-good economy reports base-year and current-year quantities and prices.
In the base year, 100 solar lamps sell for $20 and 50 filters sell for $30. In the current year, 120 lamps sell for $25 and 60 filters sell for $33. Calculate current nominal GDP, current real GDP at base-year prices, and the GDP deflator.
Show your working.
Interpret the GDP deflator.
A. Use current quantities with current prices for nominal GDP, current quantities with base-year prices for real GDP, then calculate nominal GDP ÷ real GDP × 100.
✅ Correct! 😊 This keeps the quantity basis constant while changing the price basis. It gives nominal GDP of $4,980, real GDP of $4,200, and a deflator of about 118.6.
B. Use base-year quantities with current prices for real GDP, then divide real GDP by nominal GDP.
❌ Not quite 😭 Real GDP for the current year requires current quantities valued at base-year prices. The proposed ratio also inverts the GDP deflator formula.
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C. Add all four prices and quantities, then report the percentage change in the total as the deflator.
❌ Not quite 😭 GDP aggregates price multiplied by quantity for each final good; raw prices and quantities cannot simply be added. A deflator is an index ratio, not that mixed total’s growth rate.
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D. Calculate nominal GDP only and treat its rise from the base year as real economic growth.
❌ Not quite 😭 Nominal GDP changes with both quantities and prices. Without the base-year price adjustment, the response cannot isolate real output change.
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Full explanation
- Step 1Current nominal GDP = 120 × $25 + 60 × $33 = $4,980.
- Step 2Current real GDP = 120 × $20 + 60 × $30 = $4,200 in base-year prices.
- Step 3GDP deflator = $4,980 ÷ $4,200 × 100 ≈ 118.6.
- Step 4Interpret 118.6 as a price level about 18.6% above the base-year level, not as an inflation rate of 118.6%.
Practice 2: Evaluate expansionary fiscal policy
An economy has falling household confidence, unemployment, and output below its sustainable production level.
Using an aggregate demand and aggregate supply diagram and a real-world example, evaluate the use of higher government spending to reduce unemployment.
Explain the policy transmission mechanism.
Support the response with economic reasoning.
A. Diagnose a demand-side gap, show government spending shifting aggregate demand right, trace output and employment effects, then evaluate the multiplier, spare capacity, lags, inflation, debt, distribution, and alternatives.
✅ Correct! 😊 This selects policy only after identifying the shock and makes the transmission chain visible. The evaluation tests both the likely strength and the costs of the intervention.
B. Shift short-run aggregate supply right because government spending directly lowers all firms’ production costs.
❌ Not quite 😭 Higher government spending is initially a component of aggregate demand, not automatically a reduction in production costs. The wrong curve breaks the stated transmission mechanism.
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C. Recommend higher spending because it always removes unemployment without affecting prices or government debt.
❌ Not quite 😭 The claim ignores capacity constraints, financing, time lags, and possible inflation. A policy judgment must be conditional on the size and nature of the gap.
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D. Describe unemployment data and a real-world example but omit the aggregate model and behavioral transmission chain.
❌ Not quite 😭 Evidence and application matter, but they do not replace analysis. The response must connect spending to aggregate demand, output, employment, and other objectives.
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Full explanation
- Step 1Falling confidence reduces consumption, so diagnose a leftward aggregate-demand shock and an output gap before choosing a policy.
- Step 2Higher government spending raises aggregate demand directly and may create multiplied increases in income, consumption, real output, and employment.
- Step 3Use the diagram to show AD shifting right toward sustainable output, with the price-level effect depending on aggregate-supply conditions.
- Step 4Evaluate multiplier leakages, spare capacity, targeting, implementation lags, inflation, debt, distribution, expectations, and alternative policies before reaching a conditional judgment.
Key terms for Unit 3: Unit 3: Macroeconomics
Models, uses, and boundaries
- Connect measurement, models, and policy
- Nominal GDP adds current prices multiplied by current quantities. Key relationship for unit map: connect measurement, models, and policy.
- Real gdp separates output change from the price change captured by the deflator
- The GDP deflator divides nominal GDP by real GDP and multiplies by one hundred. Real GDP separates output change from the price change captured by the deflator.
- The multiplier converts the original change in autonomous spending into the total output change in this confidence-shock example
- The change in output equals the spending multiplier times the change in autonomous spending. The multiplier converts the original change in autonomous spending into the total output change in this confidence-shock example.
IB Economics Unit 3 FAQ
How much of IB Economics does Unit 3 carry?
International Baccalaureate does not publish a per-unit weighting for this exam.
What is the first move on a Unit 3: Macroeconomics problem?
Decide whether the prompt asks for a level, rate, index, real adjustment, curve shift, or policy transmission chain.
Which relationships should I preserve?
Nominal GDP uses current prices, while real GDP uses a base-year price structure to separate output change from price change. A spending shock shifts aggregate demand, while a production condition shifts aggregate supply. Policy evaluation connects the instrument to behavior, the model, named objectives, and a conditional judgment.
Which representations should I practice?
Practice moving among a nominal and real GDP calculation table, an aggregate demand and short-run aggregate supply diagram, a policy transmission chain from action to economic objectives.
What error should I check before submitting an answer?
Check for mistaking a nominal change for a real change; drawing a curve shift without naming its determinant; selecting a policy before diagnosing the shock.
Evidence workshop
Continue from the free model into complete practice
The full unit guide continues with the chapter’s worked examples, figures, scoring tables, and answer checks.
- Unit map: connect measurement, models, and policy (continued)
- Worked example: calculate real GDP and the deflator
- Worked example: draw and read an AD shift
Full unit practice. Open the complete guide for the full evidence workshop and synthesis.
Related IB Economics unit guides
IB Economics Exam Guide & Review
The whole exam and its official unit sequence.01Unit 1: Introduction to Economics
International Baccalaureate does not publish a per-unit weighting for this exam.02Unit 2: Microeconomics
International Baccalaureate does not publish a per-unit weighting for this exam.04Unit 4: The Global Economy
International Baccalaureate does not publish a per-unit weighting for this exam.How to study IB Economics Unit 3
Start with the organizing decision
Before solving, restate the decision in operational terms: Diagnose the measurement or shock before choosing a model, calculation, or policy response.. Your first written move should be to Decide whether the prompt asks for a level, rate, index, real adjustment, curve shift, or policy transmission chain..
Practice the same idea in several representations
Rotate through a nominal and real GDP calculation table, an aggregate demand and short-run aggregate supply diagram, a policy transmission chain from action to economic objectives. Use each representation to practice National Income Accounting and the Business Cycle, Aggregate Demand, Aggregate Supply, and Macroeconomic Equilibrium, Economic Growth and Unemployment, Inflation, Deflation, and Conflicts Between Macroeconomic Objectives, Economic Inequality and Poverty, Demand Management: Monetary and Fiscal Policy, Supply-Side Policies, The Keynesian Multiplier, the Money Market, and Sustainable Government Debt (HL), and explain what stays invariant when the surface form changes.
Turn each error into a repair check
After every attempt, audit the response for mistaking a nominal change for a real change; drawing a curve shift without naming its determinant; selecting a policy before diagnosing the shock. Then redo only the first step that made the reasoning diverge, keeping units, direction, and model conditions visible.
Confirm current course details in the official IB subject guide / subject brief for the 2027 administration.