6. The unemployment rate measures the fraction of a. the adult population that has stopped looking for work. b. the adult population that is not working. c. the labor force that has stopped looking for work. d. the labor force that is not working.

The correct answer is d. the labor force that is not working.<br /><br />The unemployment rate measures the fraction of the labor force that is not working but is actively seeking employment. It is calculated by dividing the number of unemployed individuals by the total number of individuals in the labor force.