ccer国际贸易作业一答案

1

a) 画出两国的生产可能性曲线

b) The opportunity cost of potato in terms of beef in Country A: /8/100.8LP LB a a == The opportunity cost of potato in terms of beef in Country B: /8/100.8LP LB a a ==

c) The model is under the complete competition assumption, firms earn zero profit. Ppotato equals to marginal cost. Wage is the same in the two sectors \in one country.

//8/100.8P B LP LB P P wa wa ===

*****//5/80.625p B LP LB P P w a wa ===

d) When one country can produce a unit of good more efficient than another country, we say the first country has absolute advantage in producing that good.

**&LP LB LP LB

a a a a <<, country A has absolute advantages in potato and beef. A country has a comparative advantage in producing a good if the opportunity cost of producing that good in terms of other good is lower in that country than it is in other countries.

*

*

LP LP LB LB

a a a a >, country A has comparative advantage in beef, and country B has comparative advantage in potato because country A has lower opportunity cost of producing beef than that of country B.

2

a) When *

*

*

*,,P LP LP P B P B B LB LB

P a a W W W W P a a <<<<, country A and country B are specified in producing potato, *0P P y y +=, *80100180B B

y y +=+= When *

*

*

*5,,8P LP LP P B P B B LB LB

P a a W W W W P a a ==<<=, country B is indifferent in producing

potato or beef, and country A is specified in producing beef. ******[0,160],()/,0,80P B P LP LB P B y y L y a a y y ∈=-⨯== When *

*

*

*54,,85

LP P LP P B P B LB B LB a P a W W W W a P a =<<=<>, country A is specified in producing beef, and country B is specified in producing potato. **0,160,80,0p p B B y y y y ====,

*

*()/()2p p B B y y y y ++= When *

*

*

*4,,5

LP P LP P B p B LB B LB a P a W W W W a P a <===>, country B is specified in producing potato, and country A is indifferent in producing potato or beef.

**

160,0,[0,80],()/P R B P B LB LP y y y y L y a a ==∈=-⨯, **()/()[2,)P P

B B y y y y ++∈+∞ relative supply function:

*****

*

***

***5(0,),()/()08

5,()/()[0,2]8

54,()/()285

4,()/()[2,)5P P P B B B P P P B B B LP P LP p p B B LB B LB LP P LP P P B B LB B LB P y y y y P P y y y y P a P a y y y y a P a a P a y y y y a P a ∈++==++∈=<<=++=<==++∈+∞

b)relative demand curve

1/P B P

B

P B P Q Q P Q Q ==c)

The equilibrium relative price of potato is determined by the intersection of relative demand curve and relative supply curve.

5/8

4/5

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