How is a common resource characterized?

A common resource is characterized as non-excludable and rivalrous. This means that it is not possible to prevent individuals from using the resource, which aligns with the idea of non-excludability. At the same time, because the consumption of the resource by one individual diminishes its availability for others, it is considered rivalrous.

An example of a common resource is fish in a publicly accessible ocean; anyone can catch fish (non-excludable), but if one person catches a fish, there is one less fish available for others (rivalrous). This distinction is important in understanding how common resources can lead to overuse and depletion, a situation often referred to as the "tragedy of the commons."

In contrast, other options describe characteristics that do not apply to common resources. For instance, resources that are excludable allow owners to prevent access, which does not apply to common resources that everyone can use. Similarly, the combination of being both excludable and rivalrous is a trait seen in private goods, while non-rivalrous and non-depleting characteristics pertain to public goods, which are available to everyone without reducing their availability. The framework of these classifications helps clarify the differing economic management and policy implications