John Maynard Keynes described periods of irrational pessimism and optimism that affect the investment behavior of firms as animal spirits. When considering the investment behavior of firms, animal spirits can be thought of as changes in the

The Solow residual is

A) the waste from the production process. B) the most common measure of productivity shocks. C) a measure of the efficiency of the production process. D) a measure of the proportion of involuntarily unemployed workers.

Economists began carefully calculating GDP

a. simply because the data was available b. to determine the contribution of specific firms to the economy c. as a result of the problems during the Great Depression d. to make sure that firms were being productive e. to gain insight into the causes of unemployment