Public Goods and the Free-Rider Problem
A public good has two defining characteristics: non-excludability, meaning it is impossible or prohibitively costly to stop people who have not paid from consuming it, and non-rivalry, meaning one person's consumption does not reduce the amount available for anyone else.
Before you start
Make sure you're comfortable with these topics first:
Method
- Test any good against the two characteristics one at a time: is it possible to exclude a non-payer, and does one person's use reduce what is left for others?
- Explain the free-rider chain step by step: the good is non-excludable, so individuals have an incentive not to pay for it (the free-rider problem), so a private firm cannot cover its costs from voluntary payment, so the good is not privately provided, which is a missing market rather than simply an under-provided one.
- Explain the valuation problem: because there is no market price for a public good, government must estimate its value to society using methods such as cost-benefit analysis, which is imprecise and can be distorted by how people answer hypothetical willingness-to-pay surveys.
- Distinguish pure public goods from quasi-public goods, and give a clear real example of each, explaining which characteristic is only partially present in the quasi-public example.
- Compare the two main provision routes: direct government provision, funded from general taxation, versus government funding a private contractor to provide the good; note that either route removes the exclusion problem for the end user.
- For an evaluation question, weigh the efficiency and cost discipline that competitive tendering to a private contractor can bring against the monitoring difficulty of checking a contractor delivers quality, and the risk of state inefficiency or a lack of price signal under direct provision.
Worked example
Classify a lighthouse and a toll bridge using the two tests for a public good (excludability and rivalry), and state which is closer to a pure public good.
- Test the lighthouse for excludability: a lighthouse's beam can be seen by any ship passing nearby, and there is no practical way to stop a ship that has not paid from using its light, so it is non-excludable.
- Test the lighthouse for rivalry: one ship using the light to navigate does not reduce the light available to any other ship, so it is non-rival.
- Since the lighthouse is both non-excludable and non-rival, it is a pure public good.
- Test the toll bridge for excludability: a barrier and toll booth can stop a driver who has not paid from crossing, so it is excludable.
- Test the toll bridge for rivalry: up to its capacity, one car crossing does not stop another car crossing, so it is largely non-rival until congested, making it a quasi-public good rather than a pure public good, since it is excludable even though it is close to non-rival under normal traffic.
Practice questions
Type your answer and press Check to be marked straight away, or reveal the answer and mark yourself.
Q1Define non-excludability.Show answer
Answer: It is impossible, or prohibitively costly, to prevent someone who has not paid for a good from consuming it.
Q2Define non-rivalry.Show answer
Answer: One person's consumption of a good does not reduce the amount of that good available for anyone else to consume.
Q3Give an example of a pure public good.Show answer
Answer: National defence, street lighting, or a lighthouse.
Q4Give an example of a quasi-public good.Show answer
Answer: A toll road, or a fireworks display over an open public area that becomes crowded (non-rival up to a point, but access could be restricted).
Q5Why can street lighting not be reliably provided by a private, profit-seeking firm charging individual households?Show answer
Answer: Because it is non-excludable, anyone on the street benefits from the light whether or not they paid, so the firm cannot force payment and would not be able to cover its costs, meaning the market for it is missing rather than merely small.
Q6Define the free-rider problem in one sentence.Show answer
Answer: The incentive an individual has to enjoy a non-excludable good without paying for it, relying on others to fund its provision instead.
Exam-style questions
Written in the style of a A Level Economics exam paper, with a full mark scheme.
Explain why national defence is unlikely to be provided by the free market.
Show mark scheme
Tick each line you got. Your score builds from the marks on the scheme.
Nothing ticked yet - 4 available
Assess whether the free-rider problem justifies the government directly providing all public goods, rather than funding private firms to provide them.
Show mark scheme
Tick each line you got. Your score builds from the marks on the scheme.
Nothing ticked yet - 20 available
See real A Level Economics past-paper questions, with official mark schemes →
Free printable worksheet
Want more practice on paper? Download the public goods and the free-rider problem worksheet pack - 5 pages of exam-style questions with a full mark scheme. One email opens every download in this browser for 14 days - no account, no card. Print it for personal and classroom use.
Next topics
Not quite what you needed?
Tell us what is missing on public goods and the free-rider problem, or which topic to write up next. Every request is read, and we reply to every one.
Build a full practice pack.
This topic is one of hundreds in the library - pick the ones a student needs and generate a printable PDF in minutes.