In the short run, a purely competitive seller will shut down if product price:

Since 1962, which of the following federal expenditures, measured as a percentage of GDP, has decreased?

A) Social Security B) Medicare and Medicaid C) net interest D) defense

There are 30 firms in an industry. What happens to that industry's four-firm concentration when the third- and fourth-largest firms merge?

A) Nothing, because their shares are already included in the concentration calculation. B) The industry's concentration ratio will fall. C) The industry's concentration ratio will increase. D) It is impossible to know without more information.