phân tích biến động kinh tế một cách tổng quát với mô hình tổng cung và tổng cầu


 
     !"##"$"%  &  '(  )  *+,
-./"012/2 
"%3$/4%/56/
%76/%89:
)*+:"0;<=,%->'<?
1@-A!B:"%*)6
C<"0"&2&*!
DA9EC:+:+F"%:+
"0"G+H:+<IF"%BH,A.
:E:+5"#:+<I&
"#:+J.!BA9E
C52?02$!<(&2?02$4(J9!B
!4(:+<I6/$K'/.:E
!:+6C/:"0!L:"0<(
M:N)O&PB7:!
4(  >&P  :N9"#7:7  7  :
  /!4(:N7:6    <=  
PE*":N2;7
E$&PEE

1.  !"#$%&' '(')
*+,- 
K"%EFQRHCS+/@"06O
T6."%QR:NU:+"06.<S=
9"%+(O-6
1.2 /0 &12345678 !"#%(
>G./*;<QR6C*2VA:+"0W
MV=PY
!6W

>WO/
XW+"&/FS+SH
YWO
ZW:"0
Y"G!P!)6C"0(<"$<(:+<"/
":W
9:/;
<
= 9:/;
(
=kY
X$>X+S.@2"G!PA+/S
@YZ
Y
QR
12.:"0 Z
JP[[WK"%EQR
JP[[N"%@02@YZL\2"G!P:+
"0@>X&EK"%<+*+9đưng tng cu.
2

1.3 >-28 !"#)3?#3
K"%EQRCS+/@OY"0
6.<S=ZT6"0NOS>K"%E<+
*+A!BW]@+&E.O*+.
"06<S= )
>CC+/^/S@YZ*,*_+/
@+"0/&<S] .`<S:a<=
"0$G.<6&<S?$6"06<S
="0.2

M)(6.U6C*,*_:+<"/T:
"0G.9"%/<SG"0:+<"
>bY$GX$O<I+S.:+<"/$GA
O22G.:+<"/$G2_2/"0
<SG"1:"0c2G
1.4 <@)A#BC8 !"#
K"%QR"0N"GO$:+>6T6.
"%QR+/@YZ$:+S>
TO/E.02@YZ2E.I
"%E2<SCJ\)O:+P+!6
"%EQR<SC
d:aT;!"G:+Y"G!PS"0:N
E::+<e:"GO!S:
"0<IYZ
X$O6.:"0:N2G.O$O:"0
6.:N2G]6."%EQR:NS:!"fS:W
3

Y
QR
[
QR
g
"0.12Z
JP[g<SC27!"%E
M-:E!O/c"%E<S
C(9O!"$.7:4O/>A:+
<">bY2G.<6:"02G8).7:4
O/"%QR<SC27!
T"0(.T;!"G :+:N6"%QRS

:2
/
QR
g
QR
[
D
12.:"0
JP[h<SC"%QR!27
Y"G!P:+"0U6: YZ(O
!"$.:"0:NG(`O:"0!"$.O:N2G
O/&2f+<;!@
ETO/"0@#O+S."%
Ee<SC<@E!+"&/KC
4

"0);6C"%E<SC.U:N
)OG*,*_+)/@ijD>QR!2:
1.5 <
K"%i5!+/@\:12!)S!"%6
<S=D\:P"<2)<2G:N
12+<;K"%i64+/^/S@\:
12*K"%i<+*+C/+/^/S@\:
12!)S!"%6<S=Ri"0N7:7
S.7:7E.IEd:N"%i<S
C
5
Zkl
lk8FZmHniF!
[

Hnd
JPFHN"W\
: V!
[
)!
g
"
<    V  iF!
[
H  *+  o  iF!
g
H
JPFHNC],,:W
"<ViF!
[
H*+o
iF!
g
H12VZ
[
*+  Z
g
  JP  FH  N  "%  i
C/+/@\:
12W\:.
122
l
lk8FZmHniF!
g
Hnd

FE;%F
G
+HDH<
ZZ[
Zg
!
!
!
g
!
g
!
[
!
[
i
i
iF!
g
H iF!
[
H
Z
Zg
Z[
9;I<
9;JKI
L(r)
/
M/P

Lãi suất cân bằng
Số dư ền tệ thực tế

1.6 L #BM  N OP678
**L #BM 6Q2@ N OP
d9>O/
YO
DA"7S:+<"/+SW>
<;!"GS.Y!4(&ER6.
:+<"/!+/$\:"%pO
9:/;
<
=:
DA"7!B:+<"/2=
\:D\:27G/4@.\:P/4@
':N&2<eB/a;!2C"#
\G.<6:+<"/:N"0(T6.
:+<"/6+/S$\:
9:/;
(
=
DA"7=A!B.::U/
 \:: /\:]>:N>bY
F<Y+SH."%:+<"/<SC:!.\:
;B V!
[
)!
g

6

L(r)
M/P
Lãi suất
Số dư ền tệ thực tế

**W2=2!CA"7#!).
:+<"/&@S"##\:oS"##
12]12PO)c.<69<S
G.:+<"/ )
9:/;
(
=
]12 VZ
[
)Z
g
."%:+<"/<SC!
.$O:+<"/&E.\: V!
[
)!
g
K6
+/@12\:W12 )P\::N )
K"%C<q!)/!=9*W:"0b12rW\:C/+
/@12\:!)S!"%/7"%D>6"$<+
)K"%D>"0N$7:/S.7:/F
HE:N<SC"%D>
7
!
g

!
[
>
[
bY>
g
bY
LM
Y
Thu nhập, sản lượng
L(r,Y1)
M/P
Lãi suất
Số dư ền tệ thực tế

>&PimD>5!O\:12L\:;BS!"%
6/
iW Zk8FZmHniF!Hnd W! ksiF!HkslkZ
D>W >bYkDF!.ZH WZ ksF>bYH
R
 ks! 
1.7 R1<$678 !"#S
Thu nhập quốc dân giảm khi mức giá tăng, đường tổng cầu dốc xuống:
>&PimD>"0*;<OY&E:N*_&P
!!"%02OE
(9O/>!"$.OYG:+<"
>bY2G>OO:+<"/2G<S
C"%D>)!). \:12;BT"1.
O VY
[

)Y
g
P12+<;VZ
[
*+Z
g
K"%E
CS+/^/S@12+<;OPV&
PimD>
8

A &6Q23) -Q .
@ M
!
g
!
g
!
[
!
[
DF!.Z
g
H
b
Z
[
Z
g
AD

Y
P
Thu nhập, sản lượng
Y1
LM(P=P2)
Y2
LM(P=P1)
Y
Lãi suất
Thu nhập, sản lượng
Y1
LM1
LM2
Y
Lãi suất
Thu nhập, sản lượng
AD1
Y
P
Thu nhập, sản lượng
AD2

*TUBM# 3478 !"#)A#BCS
XP"%E&PimD>)U:+<SC
"%i'"%D>"%E<SC87:7
'7:/#! 12!&PimD>.<1c
<SC"%E)!)"G"1.7:7'
/t212!&PimD>.<1c<SC
"%E27!
9

 !"#R1<$
Y
g
Y
[
i
Z
g
N2, -Q .V&W
i
>O

LM
IS2
Y
Lãi suất
Thu nhập, sản lượng
AD1
Y
P
Thu nhập, sản lượng
AD2

87:/#!W(9O!"$.O/ 
 :+<"/.<SC"%D>*+<"$12 R
1.7:/#!:N<SC"%E!27.I
$9O.E )FPH
87:7#!W72/7:7#
!.I. ):N"%i<SC!27
 12(9O!"$FPH

*R1 !#9%<;
K"%E&UO"0:2uT652
+/@:+R6.U6+/@Y
ZC(!C$"%Em67"%E
*+,- 
EFQ!,,22mQHE+"06<S=<
/2:v::*2#`O!
%S
K"%E,W"%2+/@O
E"06<S=</2:*6EE
W
%<=X9/;
Sau đây ta xem xét đưng tng cung trong dài hạn và ngắn hạn:
2.2  !# &)7->Y%<9Y#%&' '<#ZZ4B;
10
N2, 7-NV
&W
>O

i
[

!<(. :*"$S#+!
66W+.f.)))!P9&/
"$6R6!<(.O&"#:"0FE
H
!<(."%E6<(pO(O:"0 
<SC"%E!<(WM-:E!
EO:"0 c<SC"%E<
(8+6 E:"0 :N <S

C"%E!<(]6W
nZ2  K"%E<(<SC:2
nZ2 K"%E<(<SC:!
8+DwQ6W+..))).!P
9&/
nDW<<;.^//2).S"GX7<=W]
6:+"0$<;12"<C:P :+"0
."06<S= )K"%E<(<SC
)2T"0(.&;!%:P"%E<S
C)!"G"1+$7:"G.12.7
:\ .U"0$. 6."%E
!<(<SC:28o+$5//2) .:
"0E<(<SC:!"0(
nX+Wf+1f+"%C/& :
:*]f+"0 :N  :.<6:N "0
6<S=K"%E<(<SC)2"0(
11
LRAS
P
P
1
P
2
Y
sản lượng
Y
P
JPg[>&P"%E<(
LAS SAS
P

P1
P2
Y2 Yp Y1 Y
0

+:N :.+"06<S=O."%
E<(<SC:!
n)))W.:.%x]
2!L:$:N"%E<SC:2
E%6C(&/2'26 G."%E
<(<SC:!
n!P9&/WT.6C6%!P9
2!C.)G6<S="0:*!G.
"%E<(<SC:2
2.3  !#[>(SRAS: Short Run Aggregate Supply)
**+,- 
K"%E4(1202@CC<qE
(@OS!4(
**\8-C
wQ2=6.<S=!4("%E6
"$<+)I!o .: !O6
*"$ "0<S=!::U
O6*"$"0C/+/f
@:"0O
wQ:"02GOZ2XPUo
f":a<=P:ELY6CZ 
wQ<+:"0GOZ2XPUo!7
f":a<=FH):E$Y5
Z 7




12

J1*S !#[>
Phương trình SRASW
D=]^_9//
'
;6`-_abc
Z:"0.y:"0).YO.Y
,
OP9
z:+:"02O"+$@E
%O
[bzWK<+"%Q
3 đặc tính của Phương trình SRASW
mY
,
 !"$.
mYkY
,
.Zky
mYsF{HY
,
.ZsF{HY
,
**3R16Q !#

a. Lý thuyết tiền lương cứng nhắc:DA!B"%E4(<+
)P"G<I51(2|O4}!4(

51(2"G<!02f@"%
</2.<2(*\<1:&B
R"G&E,:E.)O2G
/:*,(701G<
/2"0<S=!(.: O
"G.27)!#)!~G"G2
G</2)).))(!:
"0G
13
Vì sao đưng tng cung ngắn hạn dốc lên?
Y = F (L)
Y
Y2
Y1
L1 L2 L
L= LD(W/P)
W/P
W/P1
W/P2
L1 L2 L
Y = Ῡ+ ᾳ (P – Pe)
P
P2
P1
Y1 Y2 Y

(a) #  "#  6Q
4  8W
9E;J72P?#d
9; !#


J1*R1 -Q40e[*
Phần (a) là đường cầu về lao động. Vì tiền lương danh nghĩa cứng nhắc. Sự gia tăng mức
giá từ P
1
lên P
2
là giảm tiền lương thực tế từ W/P
1
xuống W/P
2
. Tiền lương thực tế thấp hơn làm
tăng lượng cầu về lao động từ L
1
lên L
2
. Phần (b) là hàm sản xuất. Sự gia tăng của lượng cầu
14
LS1
LS2
Sự gia tăng việc làm

lao động từ L
1
lên L
2
làm tăng sản lượng từ Y
1
lên Y
2

. Phần (c) vẽ đường tổng cung phản áng
mối quan hệ giữa mức giá và sản lượng . Sự gia tăng của mức giá từ P
1
lên P
2
làm sản lượng từ
Y
1
lên Y
2
.
1
b. Lý thuyết nhận thức sai lm của công nhânWDAS"%(
%ee@"G<I"GR1O:
"%&;!4(.: "G<I<
 )"%&;I!B"G9GP
OG)!)"G<I"% 7
GO!6</2"0::U"G):N)
GC(!:"0<6"%E<+)
J1*fSR1g e2-4"hRi6`-2@- jEd he-,*
Nếu mức giá bất ngờ tăng lên, công nhân sẵn sàng cung ứng lao động nhiều hơn ở mọi
mức tiền lương thực tế cho trước, vì họ nghĩ rằng tiền lương thực tế cao hơn mức thực hiện.
Mức việc làm cân bằng do đó cũng tăng lên.
2
 FHLý thuyết thông tin không hoàn hảoW,A.:E!
O6C(%21O:PP
<q!S!"%/9:2uPR1O:
P!4(.22O(@E!OB
4:"0<S=9:N 
1 Trang 352 – Sách Bài giảng Kinh tế Vĩ mô – Nguyễn Văn Ngọc NXB Đại học Kinh tế Quốc Dân - 2007

15
W/P
L
Sự giảm sút ền lương thực tế
LD
SAS = F (P)
P
P2
P1
Y1 Y2 Y
B
A

<S= .2O<e"%E<+)
!4(
(d) Lý thuyết giá cả cứng nhắc:DA(!B
<S=c152(/EE1
(2!2<27C5.927G
F@27f272;2+&%CE
\xH'#P</2\A@02f<(
.xd</2"%ES!%6
]6.<S=*+.(
</2&C 512O/E.
)::U%!O6C:+</26
GO+.<e64G:-9S!"%.<:+
:=:*:N4:"0C(:C
6"0u)$O
**f<@)-#BC67)A#BCh8 !#[>
:<@)-#BC<Y%<
<C<9"%E2:EEO<:

EO
E:<@)A#BC<Y%<
2 Trang 355 – Sách Bài giảng Kinh tế Vĩ mô – Nguyễn Văn Ngọc NXB Đại học Kinh tế Quốc Dân - 2007
16
+-e-,# B8!-
SAS 2
SAS1
P
P
Y1 Y2
SAS 1
P
P2
P1
Y Y
SAS2

<SC"%E2:EEO<:
E+:Ef!
8!"%02:;<SC"%EW
m<SC2:VW "0/6F^
//2)H<SC"%E:2:U
"0/6F^//2) H<SC"%E
:!
m<SC2:V"W: +"0/6'
+;<SC"%E:2:U+"0"
/1'+;<SC"%E:!
m<SC2:V)))W: ))
)6<SC"%E:2:))
)/6<SC"%E:!

m<SC2:V&/W!!O&/
"%E<SC:2:U&/F<S
72H"%E<SC:!
m<SC2:VO<W::UO<
<SC"%E4(:2 O<
<SC"%E4(:!
17
SAS
Y0
P2
P1
P0
Thiếu hụt
Dư thừa
P
Y
P
P0
Yp
E0
AD
Y
SAS
LAS

*&> ,-iEk%<$%(
*iEk &[>S
!4(.(!(;BE4(BE

>O:N5O;B.=C":W

(OY
[
sY
•
PE"0E)YY
•
(OY
g
{Y
•
PE"0E)Y Y
•
JPh[!(;B!4(
*iEk &)7->S
18
l
•
Z
AD

JPhg!(;B!<(
!<(.(!(;B"%DQ4"%QR
"%QcC"%DQ"%QR
!(;BE6:<SC"%EQ
"%EQR
>OE:"0;BO;B2=
<+c"O<SC"%EQ"%EQR
;U:N)O);;!U:+
+$EEW
*,l2383-6`- !"#S

19
Y
E0
E1
AD1
SRAS
LRAS
P
Y*
AD0
P1
P0
Y1

d:a;B<((Cl
•
.:"0ZkZ€K)6
U:+V)E:<6QR<SC:!VQR
•
:QR
[
ms(!(;B$l
[
ms:"0O
C*+"0Z
[
Y
[
!G:./2 
 T6:/272.=C(S7:6C

//227"%QR<S2S!7cQR
•

TS2%7*P6C!/)
U:+6"0&2=(!(
 T&6:/2872Pc:N6G
5:%8=C":.QR<e6<S
=&"0.(RTLS2:8RT$2t2
:*6<=.P!(/2 <"
!)!S!"%@"%(!4$
"Gms27:*.77RT)
).#!:*ms"%Q<S:2VQ
[
:
Q
g
.U(!(;B$l
h
.:"0!#O:
"0 Z€"*+Y
h

20
E2
AD1
LRAS
P3
SRAS1
SRAS2
Y

Y2
P2
P1
E3
E1
AD2
P
Y1

T"1"%QR!4(<SC:"0<
"!<(."%QR<SCEO.&"#:
"0
*f,l2383-6`- !#S
8U:+*!<:E+:E
+!
8U:+E"09U:+0.p("(
.\c.•Yl8 <$.x8U:+ E"09
U:+60.p("&/  :.x
d:a;B<((Cl
•
.:"0ZkZ€K)6
U:+V)E:<6Q<SC:!VQ
•
:
Q
[
ms(!(;B$l
[
ms:"0*+Z[.O
/2 ms!GP!(P(.:"0;P

!/O ;(2
21
SRAS1
P0
P1
Y
E0
E1
AD0
SRAS0
LRAS
P
Y*
Y1
E2
AD1
SRAS1
P0
P1
Y
E0
E1
AD0
SRAS0
LRAS
P
Y*
Y1
P2


• T6:/2872W
• O.72+!/)0:<SC
"%E4(:"0P7226/22
7B""%QRVQR
•
$S!7QR
[
V<!PO:
"0ms(!(;B$l
g
.:"0!#
:"0 .O2= )
22
AD1
YY1
E2
SRAS1
P0
P1
E0
E1
AD0
SRAS0
LRAS
P
Y*Y2

• O.72+!/)0U:+O
P4E.""%EVS!7QR
[

VC<!P
Oms(!(;B$l
g
.O!#
!(::"0/.:
:;:4G
• T&6:/272P(!(l
[
.O 
)"Gms27:*msRT :
*msQ<SC:2(O:"0P
!P5$<V(
23
SRAS1
SRAS2
Y
Y1
P0
P1
E0
E1
AD0
SRAS0
P
Y*

6(/2;7U:+.'A&
61S!"%6C5C"O:"0<"$O
BO:"0 Z€'2U:+U:+
)6:/272.=C<?7:7P

/":"0!#O :N6G
f*N2,!8AQO- M
8U:+EE;!@!.
(S7:872c*;</+)u
7:CPEm"097:ESJ7:E
S!97:67:/
87:6/+22B512)
72C"$:"0/+!4
(F[mg H.7:6"#E6.<S
=8726C9E)''f%)
C#!4EBPE!<(.66
<=5G.Uu !"#;<87:
66&=W)"$.6!2$d.8F&
HO$+E
87://+22&=AI&
/<;!"G#BES!Sf.
"$:"0/+87:/$&
24
Mục êu ổn định : Y = Yp
AD2
P2
P
YY1Y2
Yp
P1
AD1

=W>OF
>
H\:F!H:N$8.i.T‚Oc$

+E
]027:S"$=)P+5
"$:NG(/G
Trưng hợp 1W]6U:+V)E:.QR<SC
:!FQR
[
 QR
g
H.<e:"0O./2 F
:H
8726C2<=7:#!W7:6#!.7
:/#!'2+027:67:/#!C
<SC"%QR!#S!7FQR
g
 QR
[
H
n87:6#!W872:N )dEQR 
25