Police protection is a private good

Falling energy prices could explain rising labor productivity in the 1990s

a. and the 1980s. b. and the 1970s. c. but not the 1980s. d. but not the 1970s.

If a firm that has variable costs of $8 million shuts down, we may conclude that its total revenue is __________.

Fill in the blank(s) with the appropriate word(s).