This graph illustrates the marginal cost,marginal private benefit,and marginal social benefit of immunization against a contagious childhood disease.
As more children are immunized,the marginal cost increases because ____ and the marginal benefit decreases because ___.

Question

This graph illustrates the marginal cost,marginal private benefit,and marginal social benefit of immunization against a contagious childhood disease. 
As more children are immunized,the marginal cost increases because ____ and the marginal benefit decreases because ___.

Quizplus · Accepted Answer

As more children are immunized, the probability of spreading the disease declines, which means the marginal private and social benefit decreases. On the other hand, the marginal cost increases because of the low-hanging-fruit principle. This principle refers to the fact that those who are most easily reached and convinced to get immunized will do so first. As more children are immunized, reaching the remaining unimmunized children becomes increasingly difficult and expensive, thus raising the marginal cost of immunization. Therefore, choice B is the correct answer.

This Graph Illustrates the Marginal Cost,marginal Private Benefit,and Marginal Social