If the MPC equals 0.75, $100 billion tax increase will decrease consumption in the first round by

When a firm generates external benefits, a more efficient outcome would result if

a. the firm produced a larger output level. b. the firm reduced its output level. c. a tax were levied on the firm equal to the dollar amount of the externalities. d. price were fixed below the firm's per-unit cost.

Between 2000 and 2013, the world added more than 100 billion tons of carbon to the atmosphere. Between 1998 and 2013, the earth's temperature

a. rose by approximately 3 degrees Fahrenheit. b. rose by approximately 2 degrees Fahrenheit. c. showed no significant change. d. fell by 1.4 degrees Fahrenheit.