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M11.L02 — Public Goods and the Free-Rider Problem

Module: Module 11 — Public Goods and Common Resources Lesson: L02 of 05 Duration: ~30 minutes Level: Introductory Provenance: OpenStax Principles of Microeconomics 3e | MIT OCW 14.01 Principles of Microeconomics

Learning Objective

Explain why markets underprovide public goods due to the free-rider problem.

The Free-Rider Problem

Public goods face underprovision because people can benefit without paying (free-riding). Since providers can't exclude non-payers, private firms lack profit incentive.

Australian examples: - ABC broadcasting: Listeners benefit even if they don't pay license fees - Street lighting: All residents benefit regardless of tax contributions - National defense: Protection extends to all citizens

Demand for public goods sums vertically (willingness-to-pay stacked) rather than horizontally as with private goods.

Worked Example

Calculating Optimal Public Good Provision 1. Three residents value additional streetlights differently: - Resident A: $150 - Resident B: $100 - Resident C: $50 2. New light costs \(250 to install 3. Sum of valuations (\)300) > Cost → efficient to provide 4. Market failure occurs if no mechanism exists to collect payments

Common Misconception

"Free-riders are just being selfish"

Free-riding is rational individual behavior - why pay if you'll benefit anyway? The problem is structural, not moral. Solutions require collective action mechanisms.

Key Takeaways

  • Free-riders enjoy benefits without contributing
  • Markets underprovide non-excludable goods
  • Optimal quantity occurs where ∑MWP = MC
  • Government provision often necessary

Practice

  1. Why don't private companies build lighthouses?
  2. How does Medicare differ from a pure public good?
  3. Calculate if a neighborhood park should be expanded when:
  4. 5 families value expansion at $200 each
  5. Expansion costs $900

Further Resources

Provenance: OpenStax Principles of Microeconomics 3e | MIT OCW 14.01 Principles of Microeconomics