Problem
Vaccinations help protect the unvaccinated from disease. Boulier et al. (2007) find that the marginal externality effect can be greater than one case of illness prevented among the unvaccinated. Is vaccination a public good? If so, what might the government do to protect society optimally?
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.