(a) Please explain how if the United States gives Covid-19 vaccines for free to

poor developing countries, that might result in benefits for both the United States and for the

developing countries. Is this an externality for the United States? You must give an explanation.

(b) Are Covid -19 vaccines in the United States a public good? Assume that there is no shortage

of vaccines in the U.S. and the vaccines are paid for either by the government or by health

insurance. Please explain.

(c) Are Covid-19 vaccines in India a public good? In India there is a shortage of vaccines, and

the public has to pay out-of-pocket for the vaccines. Please explain.