Answer
People litter along highways because individuals only consider their own benefits and costs in using the common resource of space represented by highways, but not the impact of their use on others. In this way, highways and the finite space they occupy can be considered as non-excludable but non-rivalrous, similar to a common resource facing the ‘Tragedy of the Commons’. In contrast, people’s yards are a private good being excludable and rivalrous. This means that individuals are forced to consider the private cost of littering, which deters people from littering in their backyards.
Work Step by Step
Highways resemble a common resource as being non-rivalrous and non-excludable. The large amount of litter along highways therefore exemplifies the ‘Tragedy of the Commons’. In contrast, yards are a private good which means that individuals are forced to consider the costs of the choice to litter, often deterring them from doing so.