A good is considered non-excludable if:

A good is defined as non-excludable when individuals cannot be effectively prevented from accessing and enjoying its benefits, regardless of whether they have paid for it. This characteristic is significant in understanding public goods and externalities within economics. For example, public parks provide recreational opportunities that everyone can enjoy without payment; people can use them regardless of their financial contribution.

The concept of non-excludability implies that once the good is available, it is challenging for the provider to restrict access to only those who pay for it. This can lead to issues like "free riding," where individuals benefit from a resource without contributing to its cost. This aspect differentiates non-excludable goods from private goods, where access can be controlled.

In contrast, choices that suggest the good must be freely available to all, can only be accessed by those who pay, or generates profit for its creators do not capture the essence of non-excludability. While these concepts relate to accessibility and economic viability, they do not dive into the crucial aspect of whether people can be prevented from using the good, which is central to defining non-excludability.