A recession occurred in the U.S. economy during the first three quarters of 2001. National output of goods and services fell during this period. But during the fourth quarter of 2001, output began to increase and it increased at a slow rate through the first quarter of 2003. At the same time, between March 2001 and April 2003, employment declined almost continuously with a loss of over 2 million jobs. How is it possible that output rises while at the same time employment is falling?