Money Quantity Theory

Overview

Lesson 2 of 20 in “Understanding Inflation Dynamics” builds on Lesson 1’s introduction to inflation. Today students learn the Quantity Theory of Money, MV = PY, and use it to predict how changes in money supply relate to changes in the general price level over time.

Learning intentions

• WALT analyze inflation using an economic model (Quantity Theory of Money).
• WALT identify and explain the model components: money supply (M), velocity (V), price level (P), real output (Y).
• WALT describe the implications of MV = PY under different assumptions (e.g., constant V and Y).

Success criteria

• I can define inflation in terms of the general level of prices.
• I can correctly explain what each symbol in MV = PY means.
• I can use MV = PY to justify how a change in M affects P (given assumptions).
• I can communicate my reasoning clearly using economic vocabulary.

Curriculum links

• NZ Curriculum Refresh (Social Sciences): using economic concepts and models to explain how and why economic variables change.
• NCEA AS91222 (Analyse inflation using economic concepts and models): identifying and defining inflation concepts and explaining causes of changes in inflation using economic models.

Lesson structure (75 minutes)

1. 0–5 min · Entry question. Teacher displays a prompt: “If the money supply rises but people don’t change how often they spend, what might happen to prices?” Students write a quick prediction (1–2 sentences).
2. 5–15 min · Activate prior learning + mini-lesson. Teacher revisits Lesson 1 vocabulary (inflation, real vs nominal) and introduces the Quantity Theory of Money; students copy the model MV = PY and label each variable with a brief meaning.
3. 15–30 min · Guided walkthrough (teacher modelling). Teacher derives the intuition behind MV = PY step-by-step: M×V links to spending, which becomes nominal spending equal to P×Y. Students complete a “component matching” task (cards for M, V, P, Y with definitions).
4. 30–45 min · Structured practice: two scenario cards. Teacher gives two short cases:

• Scenario A: M increases; V and Y unchanged.
• Scenario B: V increases while M unchanged; Y unchanged. Students, in pairs, fill in: “What stays constant?” “What changes?” “Which part of MV = PY moves?” “So what happens to P?”

5. 45–60 min · Reasoning check: class debrief + model accuracy. Teacher charts student answers and corrects misconceptions (e.g., distinguishing nominal output from real output; velocity not being the same as “how fast cash moves” in a casual sense). Students update their scenario responses in a “clean copy” template.
6. 60–70 min · Dyslexia-friendly reading + terminology supports. Teacher provides a short, simplified text version of the model and its implications (see Resources). Students underline key statements and build a glossary page for today’s terms (at least 3 definitions).
7. 70–75 min · Exit ticket. Students answer: “Using MV = PY, explain one cause of rising inflation in words and one assumption you must make.” Teacher collects for formative use.

Resources

• MV = PY equation card (visual model diagram)
• Scenario cards (Scenario A and B)
• Component matching cards (M, V, P, Y definitions)
• Student template: “Assumptions → Change → Price level impact”
• Simplified reading sheet (dyslexia-friendly) on Quantity Theory of Money
• Key term glossary page (blank and teacher-completed exemplar)
• Highlighters or sticky notes for annotation
• Whiteboard or slide with “Common misconceptions” list

Assessment

• Observation during pair work: check that students identify correct constants/changes and link them to P.
• Check student matching task: confirm correct definitions for M, V, P, Y.
• Exit ticket: assess understanding of both the model and at least one explicit assumption.

Differentiation

• Support:
• Provide sentence starters for scenarios: “If M increases and V and Y are constant, then MV rises, so …”
• Offer a reduced set of glossary items with teacher-friendly definitions and an example for each.
• Allow students to use a formula “fill-in-the-blanks” version: M( )×V( ) = P( )×Y( ).
• Provide the simplified reading sheet in addition to oral explanation.
• For diverse learners:
• Pair students strategically (one strong reader/one strong explainer) and rotate roles.
• Use colour coding: M and V in one colour; P and Y in another.
• Extension (advanced learners):
• Ask: “In the real world, do you think V and Y are ever truly constant? Explain one reason and how that would change the link to inflation.”
• Challenge students to create a third scenario (e.g., Y rises faster than P, or V falls) and predict the direction of inflation with assumptions stated clearly.
• EAL considerations:
• Pre-teach words: “price level”, “real output”, “velocity”, “assumption”.
• Accept explanations using diagrams first, then add correct vocabulary for final wording.

Extension (optional)

• Ask students to identify one recent example from New Zealand or a comparable economy where money/credit growth, spending, or inflation changed, and write a 5-sentence “Quantity Theory” explanation using MV = PY assumptions.