In 2012, the world's population surpassed

Compared to the initial equilibrium, an initial increase in aggregate demand that is NOT followed by an increase in the quantity of money results in new long-run equilibrium with

A) a higher price level but the same real GDP. B) a higher price level and an increased level of real GDP. C) the same price level and a lower level of real GDP. D) the same price level and the same real GDP. E) None of the above answers is correct.

The optimal quantity of pollution control occurs where: a. pollution equals zero

b. the total benefit of pollution control equals the total cost. c. the marginal social benefit of pollution control just equals the marginal social cost. d. the marginal external cost of pollution equals zero.