Public goods

Topic: Government Budget, Fiscal Policy and FRBM · NCERT: Class 7, Ch 12 "Understanding Markets"; Class 9, Ch 8 "Building Blocks in Economics: The Problem of Choice"; Class 9, Ch 9 "The Price Puzzle: What Drives the Market"; Class 12, Ch 5 "Government Budget and the Economy"

Meaning

A public good is a good that is both non-rivalrous (one person's use does not reduce the amount left for others) and non-excludable (people who do not pay cannot be stopped from using it) [5]. Examples are national defence, a public park and clean air.

It matters because free markets under-supply public goods. People can use them without paying, so private firms cannot earn enough to cover their costs [5]. This is a key form of market failure (when free buying and selling does not give the best result for society). It is the main reason for the allocation function of the government budget: the government pays for these goods through the budget.

Explanation

The two tests: rivalry and excludability

• Rivalry: one person's use reduces what is left for others.
• Excludability: people who do not pay can be kept from using the good.
• A good is a pure public good only if it passes both tests: it is non-rival and non-excludable [5].

Feature	Private goods (clothes, chocolate, cars, a cinema ticket)	Public goods (a public park, clean air, defence)
Rivalry	Rival: a chocolate I eat is not available to you	Non-rival: one person's use doesn't reduce what others get
Excludability	Excludable: no ticket, no movie	Non-excludable: non-payers can't practically be kept out
Who supplies	Market	Government (the market under-supplies)

• Clean air is the standard textbook example. When one person breathes it, the air left for others does not fall in any practical sense [5].
• Once a public good is supplied, everyone can use it, whether or not they helped pay for it [6].

Why markets fail: the free-rider problem

• Free-rider problem: people use a non-excludable good without paying and expect others to pay for it.
• Non-excludability causes free riding. Once the good exists, a person can enjoy it without paying [6].
• How the market breaks down:
• Nobody pays voluntarily for something they get free.
• So the payment link between producer and consumer breaks.
• A private firm cannot earn enough profit to cover its costs.

• So without government support, public goods are under-produced compared with the level that is best for society [5].

• What follows: the state pays for these goods through compulsory taxes instead of voluntary payments.

Lindahl equilibrium: the ideal way to pay

• Lindahl equilibrium: each person pays a tax share equal to their own marginal benefit from the public good. Marginal benefit is the extra benefit a person gets from one more unit. Provision is efficient when these tax shares together cover the cost.
• Worked example:
• A park costs ₹100.
• A values it at ₹60 and B values it at ₹40.

• Lindahl tax shares: A pays ₹60 and B pays ₹40. The total is ₹100, so the park is built.

• Why it fails in real life:

• B hides their true value and says the park is worth only ₹10.
• Total collected = ₹60 + ₹10 = ₹70, which is less than ₹100.
• The park is not built, even though it is really worth ₹100 to the two of them together.
• This is free riding again, so the state uses compulsory taxes instead.

Provision is not production

• Public provision: the good is paid for through the budget, and people use it without paying directly.
• Public production: the government itself makes the good, for example through a government department or factory.
• These two are separate. A public good can be privately produced but publicly provided.

• Example: a private contractor builds a highway, the government pays for it from the budget, and drivers use it without a toll.

• So the correct statement is that the market under-supplies public goods and the state must provide (finance) them. The state does not have to produce them itself.

In India

• The budget pays for public goods. Under the allocation function, the Union budget pays for goods the market cannot supply through normal buying and selling: national defence, roads and government administration.
• Constitutional basis: Art. 112 requires the government to present the budget as the Annual Financial Statement (AFS). The AFS for 2026-27 shows estimates for 2026-27, estimates for 2025-26 and actuals for 2024-25 [2]. This spending is financed by taxes that the Finance Bill sets out under Art. 110(1)(a) [2].
• Mixed economy: India is a mixed economy. The private sector and the government both produce and spend, side by side. Public goods are where the government's role is clearest.
• PPPs (public-private partnerships): a private firm builds the asset and the government pays for it. This is India's everyday example of "publicly provided, privately produced".
• Fiscal link: since public goods are paid for from the budget, their cost adds to government spending. That spending must stay within the fiscal rules of the FRBM Act, 2003.

Don't confuse with

• Club goods: these are excludable but non-rival only up to a congestion point (the level of use at which crowding starts to reduce each user's benefit). A toll road, cable TV and a private park are club goods, not public goods, because non-payers can be stopped at the gate.
• Merit goods: examples are education and health. They are often rival and excludable. The state supports them because society values them more than private demand does, not because of non-excludability. The tool is a subsidy.
• Demerit goods: examples are tobacco and alcohol. They are harmful and people consume too much of them, so the state taxes or bans them. An example is the 40% GST rate on sin and luxury goods, in force since 22 September 2025 [3][4]. This is the opposite of public goods, where the state pays for the good.
• Private goods: these are rival and excludable, so markets supply them well through prices. Examples are clothes, chocolate and a cinema ticket.

Prelims Hooks

• Public good = non-rival + non-excludable (both tests together) [5]. Clean air is the standard example [5].
• The free-rider problem comes from non-excludability, not from non-rivalry [6].
• Trap: "Public goods must be produced by the government" is wrong. What makes a good public is who provides and finances it, not who produces it.
• Trap: a toll road is a club good (excludable, non-rival up to congestion). It is not a pure public good.
• Lindahl equilibrium: each person's tax share = their marginal benefit. It fails in practice because people hide their true preferences.
• Providing public goods is the allocation branch in Musgrave's three functions of the budget (allocation, redistribution, stabilisation).

Mains Points

• Why the state is needed even after liberalisation: free riding means markets under-supply public goods [5][6]. So defence, basic infrastructure and administration stay funded from the budget. PPPs show that the state can provide without producing. This supports "minimum government" without weakening public goods.
• Why compulsory taxes, not voluntary payment: the Lindahl ideal breaks down because people hide how much they value a good. So public goods must be funded from general taxes, and that spending competes with other needs inside FRBM Act 2003 limits. Choosing which public goods to fund, and how much, is a central budget trade-off.
• Designing public provision: once goods are grouped by who pays, the policy follows. Public goods need budget financing. Merit goods need subsidies, which build human capital. Demerit goods need sin taxes, such as the 40% GST rate since 22 September 2025 [3][4]. Using the wrong tool leads to under-supply or wasted public money.

Related concepts

• Allocation function
• Redistribution function
• Stabilisation function
• Private goods
• Non-rivalry
• Non-excludability
• Free-rider problem
• Club goods
• Merit goods
• Demerit goods

Read more

• Why a government budget: market failure and the three functions