Florida Teacher Certification Examinations (FTCE) Social Science Practice Test

A public good is defined by two main characteristics: it is non-excludable and non-rivalrous. This means that individuals cannot be effectively excluded from using the good, and one person's use of the good does not reduce its availability to others. National defense exemplifies these characteristics perfectly. Once national defense is provided, everyone benefits from it without the risk of depletion or exclusion; regardless of how many individuals are protected, one person's usage does not detract from another's security.

In contrast, private housing is an example of a private good, as it is both excludable and rivalrous; owning a house means that other people cannot use that same property. Social security benefits are selective and depend on individual eligibility, making them not a public good by the traditional definition. Restaurant services also fall into the category of private goods, as they are provided to customers who pay for them, limiting access to only those who can afford to purchase them. Thus, national defense stands out as a clear example of a public good.