Which of the following is least likely to belong with the others?

a. Real GDP is less than potential GDP

b. The economy has been in a strong expansion for 5 years

c. The unemployment rate is above the natural rate

B does not belong with the rest of the choices. The unemployment rate being above the natural rate indicates that unemployment is slightly higher than it should be. This would indicate the economy is not necessarily in a period of expansion. Choice A also indicates that the economy is underproducing, and not in an expansionary phase. Potential GDP would be the GDP an economy has the capacity to achieve if all of its resources are in efficient use. If Real GDP, which is the accurate measure of GDP, is under potential, it is not expansionary.