Introduction
For a good to be classified as a public good, it must possess specific characteristics: non-excludability, non-rivalry in consumption, and non-rejectability. Museums, while important cultural institutions that benefit both visitors and non-visitors, do not meet these criteria and are therefore not public goods.
Non-excludability means that once the good is provided, it is impossible to exclude individuals from consuming it; national defence, for example, protects everyone and no one can be excluded. Non-rivalry in consumption means that one person's consumption does not diminish the amount available to others, as with a lighthouse that serves all passing ships. Non-rejectability means individuals cannot choose to reject the good, as with street lighting that cannot be opted out of.
Why museums are not public goods
Museums are excludable because entry barriers can be imposed. They typically charge an entrance fee, so only those who pay may access the exhibitions; this exclusion mechanism distinguishes museums from true public goods, where access cannot be restricted.
Museums are also rivalrous to some degree. Although many visitors can enjoy the exhibits at once, there are limits to how many people a museum can accommodate at any given time. If too many people visit, overcrowding reduces the enjoyment and quality of the experience for others, creating rivalry in consumption.
Museums are also rejectable, since individuals can choose whether or not to visit. Unlike public goods such as national defence, where individuals cannot opt out of the benefits, a person may simply choose not to consume museum services. Museums therefore do not fulfil the criteria of non-excludability, non-rivalry, or non-rejectability that are essential characteristics of public goods.
Museums are merit goods, which is why the government intervenes
Although museums are not public goods, governments often intervene because museums are merit goods. Merit goods are deemed socially desirable but tend to be underconsumed in a free market because the private benefits received by individuals are lower than the overall social benefits.
Museums generate positive externalities, meaning that their consumption produces benefits that spill over to society as a whole. A positive externality arises where a third party benefits from the consumption or production of a good or service. For example, when someone visits a museum and learns about their country's history, they may develop a deeper sense of national identity and unity, which positively affects the broader community, and the knowledge gained can be shared with others who have not visited, amplifying the societal benefit.
Without intervention, individuals consume museums at Qm, where their marginal private cost (MPC) equals their marginal private benefit (MPB). MPC represents the cost borne by an individual to visit, such as the ticket price and travel expenses, while MPB represents the individual's personal satisfaction from visiting. Because of positive externalities, the marginal social benefit (MSB), which includes both private and external benefit, exceeds MPB. The divergence between MSB and MPB leads to underconsumption at Qm, which is lower than the socially optimal level Qs, where marginal social cost (MSC) equals MSB. Since individuals consider only their private benefits and costs, they underconsume merit goods like museums, and this underconsumption creates a deadweight loss representing lost social welfare.
Conclusion
To correct this market failure, the government typically intervenes by providing subsidies or funding to museums. By lowering the cost of museum visits, the government encourages greater consumption, moving the quantity consumed closer to the socially optimal level Qs. Subsidies reduce the MPC, aligning it more closely with the MSB and allowing more people to benefit from museum services.