Final answer:
A positive externality is a benefit that affects people other than those directly involved in the economic transaction, such as the broader societal benefits of education, the herd immunity from vaccinations, and increased neighborhood property values resulting from individual home improvements.
Step-by-step explanation:
An example of a positive externality is the education of a student. When a government invests in public education, there are external benefits to society, not just to the individual who receives the education. Such benefits include a more informed electorate, lower crime rates, better health outcomes, and a more stable economy. Additionally, vaccinations also represent a positive externality as they protect not only the vaccinated individual but also create herd immunity, protecting those who might otherwise be vulnerable to disease. Furthermore, home improvements in a neighborhood can lead to increased property values for surrounding houses, representing another form of positive externality.