Mail delivery is considered a public good because it is non-excludable and non-rivalrous. This means that once the service is provided, it is available for everyone to use without diminishing its availability to others. The government often steps in to provide this service to ensure that all citizens have access to communication regardless of their socio-economic status.
Unlike private goods, which are produced for profit and consumed exclusively by those who pay for them, mail delivery serves a broader societal purpose. The government invests in mail services not only to facilitate communication but also to support the infrastructure of a functioning democracy. Ensuring that mail is delivered reliably and efficiently is essential for the distribution of information and goods, which in turn fosters social and economic interactions among individuals.
In conclusion, while mail delivery involves operational costs and requires funding, its nature as a service that benefits the whole society rather than one individual or a limited group classifies it as a public good produced by the government.