For society as a whole, the optimal amount of pollution control exists when:
a. the marginal cost of pollution reduction is equal to the marginal benefit of the pollution reduction.
b. firms are allowed to produce as much pollution as necessary to make the goods people want.
c. the marginal costs of pollution clean up exceed the benefits

A lower price level causes us to

A) move up along the aggregate demand curve. B) move down along the aggregate demand curve. C) shift the aggregate demand curve to the right. D) shift the aggregate demand curve to the left.

In the Keynesian model, suppose the Fed wants to keep output unchanged. If the IS curve shifts to the left, and the Fed acts to keep output unchanged, then

A. taxes will decrease. B. the real interest rate will decrease. C. taxes will increase. D. the money supply will decline.