IB Economics Government Intervention (Everything You Need for Paper 1)

Government intervention appears in almost every 15-mark Paper 1 question. This is the complete guide to answering those questions with full evaluation.

Why governments intervene

Markets left alone sometimes fail to allocate resources efficiently. Governments intervene to:

• Correct market failure (externalities, public goods, monopoly)
• Redistribute income (progressive taxes, welfare)
• Stabilize the economy (monetary and fiscal policy)
• Protect vulnerable groups (minimum wage, price floors on essentials)

Types of intervention you must know

Taxes (indirect)

What: Government adds a per-unit tax, shifting supply upward

Effect: Price rises, quantity falls, revenue generated

Use case: Correct negative externalities (smoking, pollution); raise revenue

Example: VAT on fuel increases price, reduces consumption

See our full guides on tax incidence and tax diagrams.

Subsidies

What: Government pays producers per unit, shifting supply downward

Effect: Price falls, quantity rises, government spending required

Use case: Correct positive externalities (education, public transport); protect producers (farmers)

Example: Subsidy on electric cars makes them cheaper, increases adoption

Price floor (minimum price)

What: Government sets a minimum legal price (above equilibrium)

Effect: Prevents price from falling; creates surplus; may reduce quantity

Use case: Protect producers (agricultural minimum prices); protect workers (minimum wage)

Example: Minimum wage above market wage creates unemployment

Price ceiling (maximum price)

What: Government sets a maximum legal price (below equilibrium)

Effect: Prevents price from rising; creates shortage; reduces quantity

Use case: Protect consumers from high prices (rent controls, medicine prices)

Example: Rent ceiling below equilibrium causes housing shortage, black markets

The evaluation framework (15-mark structure)

When a question asks you to evaluate a policy, always cover:

1. Define key terms — what the policy does
2. Draw the diagram — show the effect on price and quantity
3. Explain advantages (why the policy was introduced)
4. Explain disadvantages (unintended consequences, costs)
5. Use real-world example — show it works or fails in practice
6. Evaluate — judge whether benefits outweigh costs

Common advantages to include

For taxes correcting externalities:

• Reduces consumption of harmful good
• Raises government revenue for public goods
• Encourages producers to reduce pollution
• Internalizes the external cost into the market price (efficient outcome)

For subsidies correcting externalities:

• Increases consumption of merit good (positive externality)
• Lowers costs for consumers (equity: low-income access)
• Encourages production/innovation in socially beneficial sectors

For price controls (protectionist):

• Protects vulnerable groups (minimum wage protects workers)
• Prevents price exploitation (price ceiling on medicine)
• Supports domestic producers (price floor on agriculture)

Common disadvantages to include

• Deadweight loss: Quantity moves away from equilibrium → welfare loss
• Administrative burden: Government must monitor compliance, enforce rules
• Unintended consequences: Black markets, evasion, substitution
• Distorts incentives: Minimum wage → unemployment; price ceiling → shortage; subsidy → dependency
• Regressive effects: Tax that hits poor people disproportionately (fuel tax)
• Revenue cost: Subsidies and price floors require government spending

Real-world examples for exams

How to structure your evaluation

Top-band evaluation language

• "It depends on..." (elasticity, time horizon, replacement goods)
• "However, this assumes..." (rational actors, perfect information)
• "An unintended consequence is..." (substitution, black markets)
• "The distributional impact is..." (who wins, who loses, fairness)
• "In practice, success has been mixed..." (real evidence)