(5) A free rider enjoys the benefits of a good or service without paying for it. The free-rider problem is that the economy provides an inefficient small quantity of a public good.

(3) In a duopoly if the firms have agreed to jointly maximize profits, then each firm can increase its current profits by producing more. Use the following table to answer question (4) and (5). Listed in the table are the long-run total costs for two firms.