# Macroeconomics

> IB Economics HL · IB Economics Higher Level
> Source: https://www.owlsprep.com/study/ib-economics-hl-u3-overview/
> Weight: 25-30% of overall IB Economics HL exam

This unit introduces the study of economy-wide economic outcomes, core government policy objectives, and frameworks to analyze and address issues like growth, unemployment, inflation, and inequality.

**Prerequisites:** [Foundations of microeconomics (Unit 2)](https://www.owlsprep.com/study/ib-economics-hl-u2-overview/)

## Learning objectives

- Explain the core macroeconomic objectives that guide government economic policy
- Build and apply the AD-AS model to analyze economy-wide outcomes and shocks
- Evaluate the impacts, strengths, and limitations of demand-side and supply-side policies
- Analyze short-run and long-run trade-offs between key macroeconomic objectives (HL)
- Perform quantitative calculations for key macroeconomic indicators and policy impacts (HL)

## Unit at a Glance

Macroeconomics studies the big picture of the entire national economy, rather than individual consumer and firm behavior. We start by defining the core objectives governments aim to achieve, then build the foundational aggregate demand-aggregate supply (AD-AS) model that underpins all macroeconomic analysis.

After exploring equilibrium and key outcomes (economic growth, unemployment, inflation), we examine how different types of policy are used to meet macroeconomic objectives, before turning to HL-only topics including the Phillips curve, quantitative analysis, and policy trade-off evaluation.

This unit includes the following core and HL-only sub-topics:
- [Macroeconomic objectives](https://www.owlsprep.com/study/ib-economics-hl-u3-macroeconomic-objectives/) — Learn the four core macroeconomic objectives and how they are measured.
- [Aggregate demand](https://www.owlsprep.com/study/ib-economics-hl-u3-aggregate-demand/) — Understand the components of aggregate demand and factors that shift the AD curve.
- [Aggregate supply](https://www.owlsprep.com/study/ib-economics-hl-u3-aggregate-supply/) — Distinguish between short-run and long-run aggregate supply and their shift determinants.
- [Macroeconomic equilibrium](https://www.owlsprep.com/study/ib-economics-hl-u3-macroeconomic-equilibrium/) — Explore how AD and AS interact to determine equilibrium output and price levels.
- [Economic growth](https://www.owlsprep.com/study/ib-economics-hl-u3-economic-growth/) — Analyze the causes, benefits and costs of long-run and short-run economic growth.
- [Unemployment and employment](https://www.owlsprep.com/study/ib-economics-hl-u3-unemployment-and-employment/) — Examine types, causes and consequences of unemployment for the economy.
- [Inflation and deflation](https://www.owlsprep.com/study/ib-economics-hl-u3-inflation-and-deflation/) — Understand the causes, types and impacts of sustained changes in the general price level.
- [Fiscal policy](https://www.owlsprep.com/study/ib-economics-hl-u3-fiscal-policy/) — Learn how governments use spending and taxation to influence macroeconomic outcomes.
- [Monetary policy](https://www.owlsprep.com/study/ib-economics-hl-u3-monetary-policy/) — Explore how central banks adjust interest rates and the money supply to meet policy goals.
- [Supply-side policies](https://www.owlsprep.com/study/ib-economics-hl-u3-supply-side-policies/) — Examine policies designed to increase the long-run productive capacity of the economy.
- [Income and wealth inequality](https://www.owlsprep.com/study/ib-economics-hl-u3-income-and-wealth-inequality/) — Analyze the causes, consequences and policies to address income and wealth disparities.
- [Phillips curve (HL only)](https://www.owlsprep.com/study/ib-economics-hl-u3-phillips-curve/) — Explore the short-run and long-run relationship between inflation and unemployment.
- [Macroeconomics quantitative analysis (HL only)](https://www.owlsprep.com/study/ib-economics-hl-u3-macroeconomics-quantitative-analysis/) — Calculate key macro indicators, multiplier effects, and the impact of AD/AS shifts.
- [Policy trade-offs and evaluation (HL only)](https://www.owlsprep.com/study/ib-economics-hl-u3-policy-trade-offs-and-evaluation/) — Evaluate conflicting objectives and compare the effectiveness of different policy types.

## Common pitfalls

- **Wrong:** Confusing short-run (SRAS) and long-run (LRAS) aggregate supply curves
  - Why it fails: Mixing up SRAS and LRAS leads to incorrect analysis of how economic shocks impact output and prices
  - Correct: Remember LRAS is vertical at potential output, while SRAS is upward-sloping due to sticky wages and prices in the short run
- **Wrong:** Treating all policies as purely demand-side or purely supply-side
  - Why it fails: Most policies impact both aggregate demand and aggregate supply, leading to incomplete evaluation
  - Correct: Always consider both demand-side and supply-side effects when evaluating the impact of any policy
- **Wrong:** Confusing a one-time relative price increase with inflation
  - Why it fails: Inflation is a sustained increase in the general price level, not just a price rise for a single good
  - Correct: Use the definition of ongoing growth in the overall price level to correctly identify inflation

## Cheatsheet

| Concept/Formula | Description |
| --- | --- |
| $AD = C + I + G + (X - M)$ | Aggregate demand equals the sum of consumption, investment, government spending, and net exports |
| LRAS = Potential output ($Y_p$) | Long-run aggregate supply is fixed at the economy's maximum sustainable output |
| Growth rate = $\frac{GDP_{new} - GDP_{old}}{GDP_{old}} \times 100$ | Percentage change in real GDP measures annual economic growth |
| Unemployment rate = $\frac{Unemployed}{Labor\ force} \times 100$ | Standard calculation of unemployment as a share of the active labor force |
| Inflation rate = $\frac{CPI_{new} - CPI_{old}}{CPI_{old}} \times 100$ | Percentage change in the consumer price index measures inflation |
| Budget balance = $T - G$ | Difference between government tax revenue and spending for fiscal policy |
| Short-run Phillips curve = Inverse inflation-unemployment trade-off | Short-run trade-off that disappears in the long-run at the natural rate of unemployment |
| Spending multiplier = $\frac{1}{1-MPC}$ | HL-only formula for the total impact of a spending change on aggregate output |

## What's next

Start this unit by learning the core macroeconomic objectives that all government policy aims to achieve. Once you complete all sub-topics in this unit, you will move on to Unit 4: International Economics, which applies macroeconomic principles to cross-border trade and finance.

- [Macroeconomic objectives (first sub-topic of this unit)](https://www.owlsprep.com/study/ib-economics-hl-u3-macroeconomic-objectives/)
- [Aggregate demand](https://www.owlsprep.com/study/ib-economics-hl-u3-aggregate-demand/)
- [Aggregate Supply](https://www.owlsprep.com/study/ib-economics-hl-u3-aggregate-supply/)

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