IS?LM???(Y0, i0)?????????????,????????????????,?????????????????????

1
?4? IS-LM???

• ????????
• IS?LM???(Y0, i0)?????????????,????????????????,??
  ???????????????????
• ???,??????????????,??????????????????????

????GDP?YF???????,??????Y0YF??????????????????????
???????????????????????? ?????????????????????
IS
LM
E
r0
Y0
YF
2
?4? IS-LM???

• ????
• ???????????????????????????????????????,IS????????
  ???
• G? or T? ? YD? ? IS????????????

??I????????,G????????DG/(sm)????????, YF-Y0
DG/(sm)
IS'
IS
LM
E
E'
YF
3
?4? IS-LM???

• ????
• ???????????????????????????????????????,IS????????
  ???
• G? or T? ? YD? ? IS????????????
• ????Y????,???i??????(Y?,i?)

??I????????,G????????DG/(sm)????????, YF-Y0
DG/(sm) ???,???????i???????,?????I????,??????????
??Y(YF-Y1)??????? G???????(Y1-Y0)????
???1/(sm)????????????
IS'
IS
LM
E'
E
E'
YF
4
?4? IS-LM???

• ????
• ???????????????????????????????????????,IS????????
  ???
• G? or T? ? YD? ? IS????????????
• ????Y????,???i??????(Y?,i?)

????????i?????????????????,????????????????,??????
????????????????????? i??I?? Y? ??????????????????
??,??????i??????,????I??????????????????????(crow
ding out)???? ????,?????????????????????
IS'
IS'
IS
LM
E"
E'
E
YF
5
?4? IS-LM???

• ????G???????,?????YD???????,IS???????????

YD'
YD
IS ??
(Y0, i0)
i0
(Y1, i1)
i1
II(i)
6
?4? IS-LM???

• ????G???????,?????YD???????,IS???????????

YD
YD'
G? ? Y? ? L? ?
i?
? Y? ? I?
IS
LM
i'
i
II(i)
7
?4? IS-LM???

• ????
• ??????????????????,(1)??????????,(2)?????????????
  ?

????????????????
????????????????
LM
LM
C
C
A
A
B
B
?????????????
?????????????
???????
???????
8
?4? IS-LM???

• ????
• ??????????????????,(1)??????????,(2)?????????????
  ?

??????????????
??????????????
LM
LM
C
C
A
A
B
B
?????????????
?????????????
???????
???????
9
?4? IS-LM???

• ????
• ??????????????????,(1)??????????,(2)?????????????
  ?
• ???,???????,???????????????????????????
• (1)????G???????,Y??????,????????????re????????????
  
• (2)??????????????????????
• (1)?(2)???
• ? ??/??????????????
• ? ???????????????????????????????

10
?4? IS-LM???

• ??/?????
• ??????????????????????????

???????????? ???????re??????? ??/?????????????? I
S????????????? ???????????????G?????????? ????????
?,????I????????,?????????????
YD'
YD'
YD
YD
IS ??
(Y0, i0)
i0
(Y1, i1)
i1
II(i, re1)
II(i, re0)
11
?4? IS-LM???

• ??/?????
• ??????????????????????????

???????????? ???????re??????? ??/?????????????? I
S????????????? ???????????????G?????????? ????????
?,????I????????,?????????????
????????,IS???????????????,Y?????????????????????
?,IS???????????????,Y??????????????? ??,??????????
???????,????????????????????????Y?i??????????????,
?????????,????IS?????????????????????????
LM
12
?4? IS-LM???

• ????
• ?????,??????????????H??????????????i?????????????
  
• ???????,???????M???????,LM????????????
• ???? M? ?? i? ?? I? ?? Y?

????????,???????,??????????????
IS
LM
LM'
E
r1
E'
r2
Y2
13
?4? IS-LM???

• ???????
• ????????(G???),?????(M???)?????GDP?????????,???i??
  ??????????
• ??????????????,IS?????????????i????,?????????????
  ?????????????????,?????????????,LM???????????????
  ???????????????,GDP????????????????

IS'
??1990????????,????????????????,??????????????????
?????,??????????????????????????????
IS
LM
LM'
r0
E'
E
YF
14
?4? IS-LM???

• ????????
• ?????G???T????????GDP????/????????????
• ??,G gt T ????,???????????????????????????,????????
  ?????????????
• ?????B?????G,??T?????
• B-B-1 iB-1G-T
• B?????????(????) G????(???)
• B-11???????(????) T??(???) i???

15
?4? IS-LM???

• ????????
• 1990??,????????????????????????????????????,??????
  ????2001??????????380??,??????????????666?????????
  ?????
• ??1???????????????
• ????????,???????????????????,?????????????????????
  ??????,???????????????????
• ????????????,?????????????????????????????????????
  ??????????????????????
• ??2?????????????????
• ??????????????????????,???????,??????????????????
  ???????,???????????????????????????????????
• ???,???????????????????????????

16
?4? IS-LM???

• ????????
• ??????,???????????????????,?????????????????,?????
  ??????????????????
• ??????????????????????
• ???????GDP???????????????GDP????g????, Y(1g)Y-1
• B-B-1 iB-1G-T
• ?
• B/Y-B-1/Y-1(i-g)B-1/Y(G-T)/Y
• ????GDP??????2??????????
• (1)???i??????g?????????
• (2)??????????(G-T)????????

17
?4? IS-LM???

• ???????????
• ???????,????????(???????)?1??????????????????????,
  ???1?????????????????????????
• ???????????????????????????????????????,????????
  ?,????????????????????????????????
• ??,????,????,??????????????????????????IS?????????
  ??????????
• ????????
• ????
• ???????3?????,?? iS (??)
• ???????1????,?? iL (??)
• ???1????,???????????????????????

18
?4? IS-LM???

• ????????
• ???????3?????,?? iS (??)
• ???????1????,?? iL (??)
• ???1????,???????????????????????

(1i1S/4)(1i2S/4)(1i3S/4)(1i4S/4)
(1i1S/4)(1i2S/4)(1i3S/4)
(1i1S/4)(1i2S/4)
1?
(1i1S/4)
1?
(1iL)
19
?4? IS-LM???

• ????????
• ???????3?????,?? iS (??)
• ???????1????,?? iL (??)
• ???1????,???????????????????????

(1i1S/4)(1i2S/4)(1i3S/4)(1i4S/4)
(1i1S/4)(1i2S/4)(1i3S/4)
(1i1S/4)(1i2S/4)
1?
(1i1S/4)
1?
(1iL)
20
?4? IS-LM???

• ????????
• ???????3?????,?? iS (??)
• ???????1????,?? iL (??)
• ???1????,???????????????????????
• 1iL (1i1S/4)(1i2S/4)(1i3S/4)(1i4S/4)
• log(1iL)log(1i1S/4)(1i2S/4)(1i3S/4)(1i4S/4)
  
• iL(i1Si2Si3Si4S)/4
• ???????????????????,??????????????????????????????
  ????????????????????
• ????(iL gt i1S)????,(i2Si3Si4S)/3 gt i1S
  ???????,??????????????????????????? iL gt i1S ?
  iS?
• ??,????(iL lt i1S)????,(i2Si3Si4S)/3 lt i1S
  ???????,??????????????????????????? iL lt i1S ? iS?

21
?4? IS-LM???

• ????????
• ????(iL gt i1S)????,(i2Si3Si4S)/3 gt i1S
  ???????,??????????????????????????? iL gt i1S ?
  iS?
• ??,????(iL lt i1S)????,(i2Si3Si4S)/3 lt i1S
  ???????,??????????????????????????? iL lt i1S ?
  iS?
• ????????,???????????????????????????????????????(
  yield curve)??????????????????????????????????????
  ??????????
• IS????????????????????????????????,Y????????i?????
  ????????????,?????????????????????????????

22
?4? IS-LM???

• ????????
• ????(iL gt i1S)????,(i2Si3Si4S)/3 gt i1S
  ???????,??????????????????????????? iL gt i1S ?
  iS?
• ??,????(iL lt i1S)????,(i2Si3Si4S)/3 lt i1S
  ???????,??????????????????????????? iL lt i1S ?
  iS?
• ????????,???????????????????????????????????????(
  yield curve)??????????????????????????????????????
  ??????????

??http//www.risk-neutral.co.jp/php/yldcrv.html
23
?4? IS-LM???

• ?????
• iL(i1Si2Si3Si4S)/4
• ??????????i1S?????????(???i2S,i3S,i4S??????)??????
  ?,????iL??????????
• ??,????i1S?????????(???i2S,i3S,i4S?i1S???????)????
  ???,????iL????????????????
• ?????,????????????????,???????????????????
• ?????,????(??????)???????????????????????????????
  ??????????,??????????????
• ???,?????????????????????????????????????,????????
  ???????????????????????????????????????,??????????
  ????????????????????????(liquidity trap)??????

24
?4? IS-LM???

• ????????????????
• (1)???????????????
• ?????????,????????????????????????i??????,????????
  ??????,??????????????,??????????????????,?????????
  ????????????????????????????
• ????,LM???????????

LM
LL(Y1, i)
LL(Y0, i)
25
?4? IS-LM???

• ????????????????
• (1)???????????????
• ?????????,????????????????????????i??????,????????
  ??????,??????????????,??????????????????,?????????
  ????????????????????????????
• ????,LM???????????

??????(???????liquidity trap)???????,?????????????
???,???i?????????????,????????????? 1999????,?????
?????????,???????????????????,??????????????
IS
LM
LM'
E
i0
YF
26
?4? IS-LM???

• ????????????????
• (2)??????????????
• ???????????????????????????????????,?????????,????
  ??????????????,???????????????????,??????????,IS??
  ?????????

??????????,???i????????????Y??????????? ????,?????
???,???????????,???i??????,??????????????,????????
?????
LM
LM'
IS
E
E'
27
?4? IS-LM???

• (2)??????????????
• ???????????????????,??????????,IS???????????

YD
IS
(Y, i0)
i0
(Y, i1)
i1
II(i)
28
?4? IS-LM???

• ???

? ? ? ? IS-LM??? ? ? ???
???????? ??????G? ?? T? IS??????? ???? ??????Y? ????? i? ??????????
???????? ????????? M? LM??????? ???? ??????Y? ????? i? ? ????? ? ??????????????