unless you buy it first. A radio signal is not excludable; the signal is there
for anyone to access.
Private Goods
Most goods and services that you consume are both rivalrous and
excludable. Your consumption of food, clothing, a rental apartment, a car,
gasoline, airline tickets, and textbooks are only possible because you pay
the seller for the right to own those goods or services. Furthermore, your
consumption of those goods reduces the amount available for others. In
Table 16-1 , we simply refer to these goods as private goods.
Goods that are both rivalrous and excludable—private goods—pose no particular problem for
public policy.Common-Property Resources
Goods that are rivalrous but non-excludable pose an interesting challenge
for public policy. In Table 16-1 , the examples of these goods include
such things as fisheries, wildlife, rivers and streams, and so on. These are
called common-property resources.
Because no one person or firm “owns” these resources, there is no
incentive for any one user to prevent its overuse or depletion—a situation
now referred to as the “tragedy of the commons.” Tragedy of the Commons
was the title of a 1968 article in the journal Science by Garrett Hardin in
which the author described the dilemma facing villagers in pre-industrial
England. The sheep and cows owned by the villagers were allowed to