Question

some children who are vaccinated against the measles would still contract the disease if they were exposed to it. but if most children are vaccinated against the measles, the population achieves \herd immunity,\ which means that there are so few cases of the disease that even children for whom vaccinations are ineffective are unlikely to contract the disease. suppose someone says: \if most children are getting vaccinated, why does it matter if i dont get my children vaccinated?\ a. is \herd immunity\ a public good? herd immunity is a. not a public good because not everyone can consume herd immunity whether or not they pay for it. b. a public good because a person receives some immunity from the disease by being vaccinated, even if other people are not vaccinated. c. a public good because immunity is nonexcludable, and everyone can simultaneously enjoy the \herd immunity.\ d. not a public good because immunity is nonexcludable, but in order for it to occur there must be a herd, and there is no guarantee that enough people will get vaccinated.

Explanation:

A public good has two key characteristics: non - excludability (it is difficult or impossible to prevent people from using it) and non - rivalry (one person's use does not reduce the availability for others). Herd immunity is non - excludable (once achieved, everyone in the population benefits regardless of whether they were vaccinated or not) and non - rival (one person's benefit from herd immunity does not reduce the benefit for others).
Option A is incorrect because herd immunity is non - excludable. Option B is incorrect as it focuses on individual vaccination immunity rather than herd immunity. Option D is incorrect because the definition of a public good does not depend on the guarantee of its provision.

Answer:

C. a public good because immunity is nonexcludable, and everyone can simultaneously enjoy the "herd immunity."