If a small change in price will lead to an infinite change in the quantity demanded, then the demand curve is:
a. horizontal.
b. vertical

A contractionary supply shock would most likely result in

A) an increase in aggregate demand B) an increase in national income C) an increase in GDP D) a decrease in the general price level E) a decrease in employment

The marginal propensity to consume (MPC) is defined as the fraction of

a. extra income that a household consumes rather than saves. b. extra income that a household either consumes or saves. c. total income that a household consumes rather than saves. d. total income that a household either consumes or saves.