Lesson Plan

• Describe the two key characteristics of public goods and explain why they lead to market failure.
• Explain the free‑rider problem and its effect on the quantity supplied.
• Compare market outcomes with government‑intervention outcomes using the MSB = MSC condition.
• Evaluate at least three government interventions that can correct non‑provision of public goods.
• Apply the concepts by sketching a supply‑demand diagram showing the market quantity (Qₘ) and the socially optimal quantity (Q*).

• Projector and screen
• Whiteboard and markers
• Handout with summary table and diagram template
• Calculator or spreadsheet (optional for welfare calculations)
• Sticky notes for group brainstorming

Start with a quick poll: “What services in our community do you use without paying directly?” Connect the responses to non‑excludable goods, recall previous learning on market failure, and state that today students will explore why such goods are under‑provided and how government can intervene.

1. Do‑now (5') – Students write examples of public goods on sticky notes and share them.
2. Mini‑lecture (10') – Define non‑excludability, non‑rivalry, free‑rider problem; introduce MSB = MSC.
3. Guided analysis (12') – Compare market vs government outcomes using the provided table; calculate a simple dead‑weight loss example.
4. Intervention activity (15') – In groups, each selects one government intervention, creates a brief pros/cons poster, and presents.
5. Diagram sketch (8') – Students draw the supply‑demand diagram showing Qₘ and Q* and label MSB and MSC.
6. Check for understanding (5') – Quick quiz or exit‑ticket with two conceptual questions.

Recap that public goods are under‑provided because of free‑riding, but government actions can move provision toward the social optimum. Ask students to write an exit‑ticket stating which intervention they consider most effective and why. For homework, have them locate a real‑world public good and evaluate the current method of provision.