Which of the following is a public good?

Assume that the government of the state of New Jersey has determined that a large number of injuries and deaths have occurred as a result of accidents involving the installation and repairs of electrical equipment at private residences

In reaction to this problem the state assembly decided to pass a law which made a requirement that all certified electricians take and pass a tougher state licensing examination. Analyze the impact that this law is likely to have on the market for electricians and explain why safety may not necessarily improve.

In which case did the U.S. Supreme Court decide the Constitution was "intended to endure for ages to come and, consequently, to be adapted to various crises of human affairs"?

(a) Nebbia v New York (1934) (b) Munn v Illinois (1877) (c) McCulloch v Maryland (1819) (d) Dartmouth College v Woodward (1819)