A homeowner plants a tree in their yard, but the fallen leaves create a mess for their neighbors to clean up. Which of the following best classifies this situation in terms of externalities?

This situation can be classified as a negative externality in consumption because the homeowner's decision to plant a tree affects their neighbors in an unwanted way. When the tree sheds leaves, it creates extra work for the neighbors who have to clean them up, even though they did not choose to plant the tree. This means that the homeowner's action has a negative impact on others without compensating them for the inconvenience. For example, if the tree drops a lot of leaves in the fall, a neighbor might spend hours raking them up, which is time and effort they did not plan to spend. Thus, the homeowner's enjoyment of the tree comes at a cost to the people living nearby.