If net foreign investment in the United States is positive, how must national saving and
domestic investment be related? (Assume that the capital account is zero and net
transfers are zero.)
A) Domestic investment and national saving must also be positive.
B) Domestic investment must be less than national saving.
C) Domestic investment must be greater than national saving.
D) Domestic investment can be greater than or less than national saving.
Joan Jillson owns a coffee shop. Assume that the marginal product of the labor Joan
employs (MPL)equals 500 cups per week and the marginal product of her shop’s capital
(MPK) equals 1,000. Assume also that the wage (w) Joan pays her workers equals $250
per week and the rental price () of her capital – her coffee machines – equals $500 per
week. Which of the following correctly analyzes whether Joan is minimizing her costs?
A) No, Joan is not minimizing her costs because MPK is greater than MPL and is
greater than w.
B) Yes, Joan is minimizing her costs because MPK/ equals MPL/w.
C) No, Joan is not minimizing her costs because MPLw is less than MPK .
D) Yes, Joan is minimizing her costs because the she is a price-taker in the markets for
labor and capital.