What happens when a maximum price is set below equilibrium?

A maximum price (price ceiling) set below the equilibrium creates excess demand — a shortage. At the lower price, quantity demanded exceeds quantity supplied. This leads to non-price rationing (queues, waiting lists), potential black markets, and reduced supply quality in the long run as producers face lower profit margins.

How do you draw a maximum price diagram for Edexcel IAL?

Draw a standard supply and demand diagram. Mark the equilibrium price (Pe) and quantity (Qe). Draw a horizontal line below Pe labelled Pmax. At Pmax, read off Qs (on the supply curve) and Qd (on the demand curve). The horizontal distance between Qs and Qd is the shortage. Label the shortage clearly.

Edexcel IAL Price Determination Model Answers | Economics

These model answers demonstrate how to structure responses for Edexcel International A-Level (IAL) Economics and Business exams. Each answer includes a mark scheme breakdown, PEEL structure (where applicable), annotated paragraphs, and examiner commentary explaining what earns marks at each band.

8 marks

Unit 1 · 1.3.4 Price Determination · Analysis

Analyse: the likely effects of a government-imposed maximum price on a market.

Mark Scheme Breakdown

1–2 marksKnowledge: definition of maximum price (price ceiling set below equilibrium)

3–4 marksApplication: mechanism explained with reference to supply/demand diagram

5–8 marksAnalysis: developed chain of reasoning — shortage, rationing, black markets, welfare effects

PEEL Structure

Point

A maximum price set below equilibrium creates excess demand (a shortage).

Evidence

E.g. rent controls in cities like New York or Berlin — rent capped below market rate.

Explain

At the lower price, Qd > Qs. Landlords reduce supply (less profitable), tenants increase demand (cheaper). The gap = shortage.

Link

This leads to non-price rationing (waiting lists, discrimination) and potential black markets where the good trades above the legal price.

KKnowledge

AApplication

AnAnalysis chain

DDiagram ref.

Model Answer

Para 1

A maximum price (or price ceiling) is a legally imposed upper limit on the price of a good, set below the market equilibrium. K Governments typically impose maximum prices on essential goods to protect consumers — for example, rent controls in housing markets or caps on energy prices. A

Para 2

At the maximum price (Pmax), the quantity demanded exceeds the quantity supplied, creating a shortage (excess demand). An This occurs because the artificially low price encourages more consumers to demand the good, while producers are less willing or able to supply it at the reduced price — their profit margins fall, reducing the incentive to produce. An On a supply and demand diagram, the shortage is visible as the horizontal gap between Qs and Qd at Pmax. D

Para 3

The shortage leads to several secondary effects. Since the price mechanism can no longer ration the good, non-price rationing methods emerge — such as queuing, waiting lists, or seller discrimination. An A black market may also develop, where the good is traded illegally at a price above the legal maximum, often exceeding even the original equilibrium price due to restricted supply. An In the longer run, the reduced profitability discourages investment in the market — for example, landlords under rent controls may stop maintaining properties, reducing the quality of housing stock over time. An

Examiner Commentary

This answer builds a developed chain of reasoning: max price below equilibrium → shortage → non-price rationing → black markets → reduced investment. The rent control example grounds the analysis. For full marks, a correctly labelled diagram showing Pmax below Pe with the shortage clearly marked would earn diagram credit. Note how the answer extends into long-run effects (reduced housing quality) — this depth distinguishes top-band responses.

Likely Score7–8 / 8

4 marks

Unit 1 · 1.3.4 Price Determination · Knowledge & Application

Explain: what is meant by equilibrium price and how it is determined in a market.

Mark Scheme Breakdown

1–2 marksDefinition of equilibrium (where Qd = Qs, no tendency for change)

3–4 marksApplication: how excess demand/supply adjusts price back to equilibrium

KKnowledge/Definition

AApplication

Model Answer

The equilibrium price is the price at which the quantity demanded equals the quantity supplied — the market clears with no excess supply or demand. K At this price, there is no tendency for the price to change because neither buyers nor sellers have an incentive to alter their behaviour. K

If the price is above equilibrium, there is excess supply — producers cannot sell all their output, so they reduce prices. A If the price is below equilibrium, there is excess demand — consumers compete for limited goods, bidding the price up. A In both cases, the price mechanism automatically adjusts the market toward equilibrium.

Examiner Commentary

Clear and precise. The definition correctly identifies Qd = Qs and the concept of no tendency to change. The explanation of adjustment from above and below equilibrium demonstrates understanding of the price mechanism in action.

Likely Score4 / 4

Price Determination Model Answers

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