Economics · Year 12 · The National Economy · Summer Term

The Phillips Curve

Students explore the short-run and long-run relationship between inflation and unemployment.

• National Curriculum Attainment Targets
• A-Level: Economics - Inflation and Unemployment
• A-Level: Economics - Macroeconomic Performance

About This Topic

The Phillips Curve depicts the short-run inverse relationship between the inflation rate and unemployment rate. Year 12 students use UK data from the 1960s, such as the post-war period, to plot points and draw the downward-sloping short-run Phillips Curve (SRPC). This trade-off arises because sticky wages and prices mean expansionary demand policies lower unemployment temporarily but push up inflation.

Students examine factors that shift the SRPC, including supply shocks like the 1973 oil crisis and changes in inflation expectations. They contrast this with the long-run Phillips Curve (LRPC), which is vertical at the natural rate of unemployment. Expectations adjust fully over time, eliminating any trade-off and leading to accelerating inflation. Policy implications follow: short-run stimulus offers gains, but long-run credibility matters for stable expectations.

Active learning benefits this topic because students model curves with real data in pairs, simulate shifts through group scenarios, and debate policies as a class. These approaches make abstract relationships concrete, encourage evidence-based arguments, and connect theory to macroeconomic decisions teachers and students analyze together.

Key Questions

1. Explain the short-run trade-off between inflation and unemployment as depicted by the Phillips Curve.
2. Analyze the factors that can shift the short-run Phillips Curve.
3. Differentiate between the short-run and long-run Phillips Curves and their policy implications.

Learning Objectives

• Analyze the graphical representation of the short-run Phillips Curve to identify the inflation-unemployment trade-off.
• Evaluate the impact of specific supply shocks, such as the 1973 oil crisis, on the position of the short-run Phillips Curve.
• Compare the implications of the short-run and long-run Phillips Curves for macroeconomic policy decisions.
• Calculate the natural rate of unemployment based on the vertical long-run Phillips Curve.

Before You Start

Aggregate Demand and Aggregate Supply

Why: Understanding AD/AS is fundamental to grasping how shifts in aggregate demand and aggregate supply affect inflation and unemployment.

Inflation and Unemployment Measurement

Why: Students need to know how inflation and unemployment rates are calculated and what they represent before analyzing their relationship.

Key Vocabulary

Short-Run Phillips Curve (SRPC)	A curve showing a short-term inverse relationship between inflation and unemployment. It suggests that policymakers can reduce unemployment at the cost of higher inflation, or vice versa.
Long-Run Phillips Curve (LRPC)	A vertical line at the natural rate of unemployment, indicating that in the long run, there is no trade-off between inflation and unemployment. Inflation can be higher or lower without affecting the unemployment rate.
Natural Rate of Unemployment	The unemployment rate that exists when the economy is at its potential output. It includes frictional and structural unemployment but not cyclical unemployment.
Inflation Expectations	The rate at which individuals and businesses anticipate future inflation. Changes in expectations can shift the short-run Phillips Curve.
Supply Shock	An unexpected event that affects an economy, either positively or negatively, such as a sudden increase in oil prices. These can cause stagflation, shifting the SRPC.

Watch Out for These Misconceptions

Common Misconception

A stable trade-off between inflation and unemployment exists in the long run.

What to Teach Instead

The LRPC is vertical at the natural unemployment rate due to adaptive expectations. Group simulations of expectation changes help students visualize accelerating inflation without employment gains, correcting this through peer discussion and graphical adjustments.

Common Misconception

The Phillips Curve shifts only from government demand policies.

What to Teach Instead

Supply shocks and expectation changes cause shifts. Analyzing historical charts in pairs, such as 1970s stagflation, reveals these drivers and links to AD-AS, helping students distinguish policy types via collaborative evidence review.

Common Misconception

Lower unemployment always requires higher inflation, permanently.

What to Teach Instead

Short-run rigidity enables the trade-off, but long-run adjustment prevents it. Debating policy scenarios in class exposes this nuance, as students defend positions with curves and refine ideas through rebuttals.

Active Learning Ideas

Pairs Activity: Plotting the SRPC

Give pairs UK quarterly data on inflation and unemployment from 1965 to 1980. Students plot points on graph paper, fit a curve, and label the trade-off. Pairs then predict outcomes from a demand shock and share with the class.

30 min·Pairs

Small Groups: SRPC Shift Simulation

Distribute event cards such as oil price rises or rising wage expectations to small groups. Groups draw an initial SRPC, apply events to shift it, and calculate new inflation-unemployment equilibria. Groups present shifts and vote on the most impactful event.

45 min·Small Groups

Whole Class Debate: Short-Run vs Long-Run Policies

Split the class into two teams: one advocating fiscal stimulus using SRPC logic, the other highlighting LRPC risks. Teams prepare arguments with graphs, debate for 20 minutes, then vote and debrief on policy credibility.

50 min·Whole Class

Individual Task: Personal Phillips Curve Model

Students receive recent ONS data. Individually, they construct a modern SRPC and LRPC on digital tools or paper, note potential shifts from Brexit, and write a short policy recommendation.

25 min·Individual

Real-World Connections

• The Bank of England's Monetary Policy Committee regularly analyzes inflation and unemployment data, using models that incorporate Phillips Curve relationships to set interest rates and manage the UK economy.
• During the 1970s, the UK experienced stagflation, a period of high inflation and high unemployment, which challenged the simple trade-off depicted by the early Phillips Curve and highlighted the role of supply shocks and expectations.

Assessment Ideas

Quick Check

Present students with a graph showing a short-run Phillips Curve. Ask them to label the axes, indicate a point representing high unemployment and low inflation, and then draw a new SRPC to the right, explaining what event caused this shift.

Discussion Prompt

Pose the question: 'If a government aims to reduce unemployment, what are the potential short-term gains according to the Phillips Curve, and what are the long-term risks if inflation expectations rise?' Facilitate a class debate on the effectiveness of demand-side policies.

Exit Ticket

Ask students to write down one key difference between the short-run and long-run Phillips Curves and explain why this difference is important for a central bank's policy strategy.

Frequently Asked Questions

What is the Phillips Curve in A-Level Economics?

The Phillips Curve shows the short-run trade-off: lower unemployment links to higher inflation due to sticky prices. Students plot UK data to see the SRPC slope. The vertical LRPC at natural unemployment rate stresses no long-term trade-off, informing policy analysis on demand management limits.

What factors shift the short-run Phillips Curve?

Supply shocks, like energy price hikes, and changes in inflation expectations shift the SRPC. For example, 1970s oil crises moved it up, raising inflation at each unemployment rate. Students use events to model shifts, connecting to macroeconomic shocks in UK context.

How does the short-run Phillips Curve differ from the long-run?

SRPC slopes down from nominal rigidities; LRPC stands vertical as expectations fully adjust, yielding no trade-off. This explains why short-run stimulus boosts jobs briefly but risks inflation spirals long-term. Policy focus shifts to supply-side measures for natural rate reduction.

How can active learning help teach the Phillips Curve?

Active methods like data plotting in pairs and shift simulations in groups make curves tangible. Debates on policy trade-offs build argumentation skills, while real UK data analysis reveals patterns lectures miss. Students retain concepts better through hands-on graphing and peer challenges to assumptions.