Corn is an example of a non-rival public good.
In economic terms, a public good is a produced good or service that is widely available to consumers. In defining a public good, the item will generally be called non-rival, non-excludable, or both. The identification of an item as a public good is normally for analysis purposes, since it is very difficult to find products created for sale to consumers that do not meet these criteria.
Nonrival goods can be considered easily renewable, or so abundant that one consumer’s consumption in no way inhibits the consumption of others.
When a public good is considered nonrival, it simply means that the item remains widely available for consumption by all consumers, even when a consumer has engaged in consumption of the good. Nonrival goods can be considered easily renewable, or so abundant that one consumer’s consumption in no way inhibits the consumption of others. An example would be an ear of corn harvested from a cornfield. Although one ear was consumed, there are still many more ears of corn available for consumption.
A public good is also often classified as non-excludable. This means that practically anyone can make use of the good in some way, basically universalizing this public good. Public services are a good example of non-excludable goods, since anyone can benefit from the presence of a police or fire department, regardless of their economic status or situation.
There are some basic examples of products that do not meet the basic definition of a public good. It is about obtaining professional services, such as those of a doctor or lawyer. When a person makes an appointment with any of these professionals, he is wasting that professional’s time. This same time cannot be consumed by any other person, the duration of the appointment being excludable and rivalable. Also, many medications are limited in terms of consumer access, and some require a prescription from a qualified medical professional. The fact that some are excluded from access to these drugs means that drugs of this type are considered exclusionary and rival and therefore not a public good.
Over time, technological advances have created new types of public goods. The electric light pole is an example of a public good that became commonplace in the early years of the 20th century. Since its light was available for anyone to enjoy while walking down the street, the device met the criteria of being non-excludable and unrivaled. Today, products such as software packages are often classified as public goods. This is particularly true with products such as free software, widely available to anyone who wants to use it, with no cost or savings barriers that inhibit consumption.