2.(3%) True or False: Free entry and exit causes firms to earn zero profit in the long run.
(A)O
(B)X

複選題12. (5%) Use the midpoint method to calculate the percentage change in weekly quantity of facial masks rationing between week 6 and week 1, and then use your answers to calculate the elasticity of demand assuming the quantity of facial masks rationed in week 6 and week 1 are the actual quantity demanded for each corresponding price, holding other things equal. Which of these statements are true? (A)The percentage change in quantity demanded for facial masks is greater than 70%. (B) The percentage change in quantity demanded is likely smaller if week 7 data were used. (C) The elasticity of demand has a magnitude smaller than 3. (D) The demand for facial masks is elastic. (E) None of the above.

複選題13. (5%) Use the midpoint method to calculate the percentage change in weekly quantity of facial masks rationing between week 5 and week 3, and the percentage change in quantity demanded for boxed faciai masks at Yuanlin's Ji- Sin Pharmacy before/after the new local case was a announced. Which of these statements are true? (A)The demand curve of facial masks shifted to the right after the new local case as announced. (B) The percentage change is larger at Yuanlin's Ji-Sin Pharmacy than from weekly quantity rationed. (C) The percentage change in weekly quantity between week 5 and week 3 is greater than 120%. (D) The percentage change at Yuanlin's Ji-Sin Pharmacy is smaller or equal to 150%. (E) None of the above.

14. (5%) Which of the following statement(s) is true? (A)Announcing a price change in January on December 9 shifts current demand to the left.(B)Announcing a price change in January on December 9 cause current shortage due to price control. (C) Implementing a new price and increasing the amount expropriated after New Year's weekend shifts both demand and supply to the right, so equilibrium quantity increases.(D) After the long weekend of New Year's Day, supply shifts in a magnitude larger than demand. (E)None of the above.

1.(3%) True or False: Perfect competition requires perfect substitutes.(A)O(B)X

3.(3%) True or False: Under perfect competition, demand and supply are both perfectly elastic.(A)O(B)X

4.(3%) True or False: Full information is not required to achieve perfect competition.(A)O(B)X

5. (3%) True or False: Externalities cause inefficiency only because of incomplete markets. If markets were complete, there would be no market failure.(A)O(B)X

6. (3%) True or False: Allocation of common resources and public goods are inefficient only because property rights are not well defined, If property rights are well defined, markets of these goods would be efficient.(A)O(B)X

7.(3%) True or False: Natural monopoly is not a monopoly.(A)O(B)X

8.(3%) True or False: Most markets in reality are best described as monopolistic competition.(A)O(B)X