Economics Externalities Questions
The main difference between a common resource and a public good lies in the level of rivalry and excludability.
A common resource is a type of good that is rivalrous, meaning that its consumption by one individual reduces its availability for others. However, it is non-excludable, meaning that it is difficult to prevent individuals from using or accessing it. Examples of common resources include fish in the ocean, clean air, or public parks.
On the other hand, a public good is both non-rivalrous and non-excludable. This means that one person's consumption of a public good does not diminish its availability for others, and it is also difficult to exclude individuals from benefiting from it. Examples of public goods include national defense, street lighting, or public radio broadcasts.
In summary, the key distinction is that common resources are rivalrous but non-excludable, while public goods are both non-rivalrous and non-excludable.