A firm has a marginal cost of $18 and charges a price of $27. The Lerner index for this firm is:

For superstar athletes

A) their entire earnings are economic rent. B) part of their earnings are economic rent. C) none of their earnings are economic rent since rent doesn't apply to labor. D) none of their earnings are economic rent since they will do some other work once they are too old to be an athlete.

Firms in a perfectly competitive industry are earning economic losses. This is

A) a signal to entrepreneurs that some of the firms in the industry should exit and the resources of these firms should move into production of other goods. B) a signal to entrepreneurs that additional resources should be brought into this industry in order to make it profitable. C) a signal that the entrepreneurs are doing a poor job and should become workers for someone else. D) a signal to government officials that a subsidy is needed for the firms in the industry.