Joe likes to sleep late in the mornings and play tennis in the afternoons. The opportunity cost of Joe attending his morning class for one hour is

If the marginal social cost of a good equals the marginal private cost of the good, then the marginal external cost of the good

A) is zero. B) equals the marginal social cost. C) equals the marginal social benefit. D) equals the marginal private benefit.

If Martin sells a shirt for $40, and his producer surplus from the sale is $8, his cost must have been

a. $48. b. $32. c. $8. d. $40.