Final answer:
The student's question involves understanding public goods,
which are characterized by being nonexcludable and non-rivalrous, unlike private goods which are excludable and rivalrous.
Step-by-step explanation:
The question concerns the characteristics that define public goods; specifically, their nature of being nonexcludable and non-rivalrous.
A good is nonexcludable when it is difficult or costly to prevent someone from using it, like national defense, which protects everyone regardless of their personal stance on defense policies.
Conversely, private goods, like a piece of pizza, can be exclusive as the owner can prevent others from consuming it.
The non-rivalrous nature of a public good means its consumption by one individual does not diminish the availability of the good for others;
national defense consumed by one person does not detract from another's safety. In contrast, private goods are rivalrous, meaning if one person consumes them, like a pizza slice, it cannot be consumed by another at the same time.
A public good is a type of good that has two defining characteristics. The first characteristic is that it is nonexcludable, meaning that it is costly or impossible to exclude someone from using the good.
For example, national defense is nonexcludable because it includes everyone and cannot protect some individuals while excluding others.
The second characteristic is that a public good is non-rival, which means that when one person uses the good, it does not reduce the amount available for others. For instance, when one person consumes national defense, it does not reduce the amount left for others.