高階ECON-DEMA-020
At the current price, quantity demanded is 80 and quantity supplied is 50. There is:
A. A surplus of 30, and the price will tend to fall.
B. Equilibrium, because 80 and 50 are both positive.
C. A shortage of 130.
D. A shortage of 30, and the price will tend to rise if the market is free to adjust.✓ 答案
解說
Shortage equals quantity demanded minus quantity supplied when demand exceeds supply: 80 − 50 = 30. Unsatisfied buyers bid the price up. A surplus would require supply greater than demand. Adding the two quantities does not measure the gap.