微观习题

1. Will a warm winter shift the demand curve for heating oil leftward or rightward? Please draw demand curve and explain the reason.

2. What will happen to the demand for baseball tickets if young people lose interest in baseball and watch basketball instead? Please draw demand curve and explain the reason.

3. What would be the effect on the equilibrium output and price if there is a rise in the income of consumer. And explain the reason.

4. What would be the effect on the equilibrium output and price if there is a $10-per-month tax on apartment rentals. And explain the reason.

5. What would be the effect on the equilibrium output and price if government says apartments can not rent more than $200per month. And explain the reason.

6. What would be the effect on the equilibrium output and price if a new construction technique allowing apartments to be built at half cost? And explain the reason.

7. What would be the effect on the equilibrium output and price if a 20 percent increase in the wage of construction workers? And explain the reason.

8. What will be the price of army boots if there is a decrease of military spending? And explain the reason.

9. What will be the price of fish if Catholics allows eating meat on Friday? And explain the reason.

10. What will be the quantity of gasoline consumption if there is an increase of gasoline tax? And explain the reason.

11. What will be the workers wage after the Black Death struck in 14th century? And explain the reason.

12. What will be the marginal costs when average costs are minimized?

13. Assume that the demand for travel over a bridge takes the form Y=1000000-50000P,where Y is the number of trips over the bridge and P is the bridge toll.

1) Calculate the consumer surplus if the bridge toll is $0,$1 and $20.

2) Assume that the cost of the bridge is $1800000. Calculate the toll at which the bridge owner breaks even.

Answer:

1) when P=0, Y=1000000, CS=0.5*1000000*20=107

when P=1,Y=950000,CS=0.5*950000*19=9025000

when P=20,Y=0,CS=0

2) When C=1800000, R=P(1000000-50000P)

That is, 18000000=P(1000000-50000P)

So, P=2.

14. In perfectly competitive market, long run cost curve is given: LTC=Q3-12Q2+40Q:

1) if price is $100, please find quantity and average cost and profit when MR=LMC

2) please find the long-run equilibrium price and quantity for individual firm

3) when demand curve is Q=660-15P, please find the number of firms in long-run equilibrium.

15. In perfectly competitive market, supply curve is given in the long run, LS=5500+300P

1) if demand curve is Q=8000-200P, please find long-run equilibrium price and quantity

2) if demand quantity is increasing, the demand curve is Q=10000-200P, please find long-run equilibrium price and quantity

16. In a perfect competitive market, suppose a firm’s cost function in short run is STC=0.1Q3-2Q2+15Q+10,please find:

1) quantity and profit in short run when the price is $55;

2) what is the price when the firm should shutdown;

3)supply function of this firm in short run.