oferta agregate
TRANSCRIPT
Oferta Agregate
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Tre modele te ASTre modele te AS
1. Modeli me paga fikse
2. Modeli me informacion joperfekt
3. Modeli me cmime fikse
( )eY Y P P
natural rate of output
a positive paramet
er
the expected price level
the actual price level
agg. outpu
t
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 3
The sticky-wage modelThe sticky-wage model
Assumes that firms and workers negotiate contracts and fix the nominal wage before they know what the price level will turn out to be.
The nominal wage they set is the product of a target real wage and the expected price level:
eW ω P eW P
ωP P
Target real
wage
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 4
Modeli me Paga fikseModeli me Paga fikse
NQS
eW Pω
P P
eP P
eP P
eP P
Atehere
Papunesia dhe outputi ne nivelin antyror
Pagat reale me pak se niveli i targetuar, keshtu firmat punesojne me shume dhe outputi rritet me shume se niveli natyrorPagat reale e tejkalojne, firmat punesojne me pak punetore dhe outputi bie.
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 6
Modeli me Paga fikseModeli me Paga fikse
Pagat reale duhet te jene kunder ciklike, duhet te levizin ne drejtim te kundert me outputin me ciklin e biznesit:– Ne periudha ekspansioniste, kur P
rritet, pagat reale bien.– Ne recension, kur P bie, pagat reale
bien.
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 7
Modeli me informacion joperfektModeli me informacion joperfekt
SUPOZIMET:
Cmimet dhe pagat jane fleksibel, tregjet jane te pastruara
Cdp ofrues prodhon nje te mire, konsumon shume te mira
Cdo prodhues njeh cmimin nominal te te mires qe prodhon, por jo cmimin e plote.
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 8
Modeli me informacion joperfektModeli me informacion joperfekt
Oferta e cdo produkti varet nga cmimi relativ: cmimi nominal pjesetuar me cmimin total
Ofruesi nuk e di cmimin kur vendis sasine e prodhimit, keshtu qe perdor, P
e.
Supozoni P rritet por P e jo.
Ofruesi mendon qe cmimet jane rritur, keshtu qe prodhon me shume. Ne kete menyre, Y do te rritet sa here qe P rritet mbi P
e.
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 9
Modeli me cmime fikseModeli me cmime fikse
Arsyet per fiksim te cmimeve:– Kontratat afatgjata midis firmave dhe
konsumatoreve– Kostot e menuve– Firmat nukduan te merzisin
konsumatoret me ndryshimin e cmimeve
Supozime:– Firma vendos cmime
(e.g. ne konkurencen monopolistike)
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 10
Modeli me cmime fikseModeli me cmime fikse
Firma vendos
kur a > 0.
Supozoni se ka dy tipe firma:• Firma me cmime fleksibel, vendos cmime
nen• Firma me cmime fikse, P dhe Y do te
jene:
( )p P Y Y a
( )e e ep P Y Y a
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 11
Modeli me cmime fikseModeli me cmime fikse
Supozoni cmime fikse presin qe outputi ne nivelin natyror. Atehere,
( )e e ep P Y Y a
ep P
s pjesa e firmes me cmime fikse.
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Modeli me cmime fikseModeli me cmime fikse
(1s )P nga te dy anet:
(1 )[ ( )]eP s P s P Y Y a
Cmime fleksibelCmimi fiks
(1 )[ ( )]esP s P s Y Y a
Pjesetuar me s :
(1 )( )e s
P P Y Ys
a
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Modeli me cmime fikseModeli me cmime fikse
P e e larte P e larte nqs firmat rrisin cmimin, atehere firmat qe duhet te vendosin cmimet te larta.Cdo firme vendos cmime te larta.
Y I larte P i larte Kur kerkesa per te mira eshte e larte firmat me cmime fleksibel vendosin cmime te larta.Sa me i larte fraksioni i frimave me cmime fleksibel, aq me e vogel eshte s dhe me e larte eshte efekti i Y ne P.
(1 )( )e s
P P Y Ys
a
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Modeli me Cmime fikseModeli me Cmime fikse
Derivoni AS duke zevendesuar ne Y :
(1 )( )e s
P P Y Ys
a
( ),eY Y P P
where (1 )
ss
a
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Modeli me cmime fikseModeli me cmime fikse
Ndryshe nga modeli me paga fikse, modeli me cmime fikse nenkupton nje model prociklike:
Supozoni se outputi agregat/te ardhurat bien. Atehere,
Firmat presin qe kerkesa te bie. Firmat me cmime fikse ulin prodhimin
dhe ulin kerkesen per pune. Zhvendosja majtas e kurbes se kerkeses
ben qe pagat reale ye bien.
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PermbledhjePermbledhje
Y
P LRAS
Y
SRAS
( )eY Y P P
eP P
eP P
eP P
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PermbledhjePermbledhje
Supozoni nje shok pozitiv te ADdhe P rritet mbi P e
Y
P LRAS
SRAS1
equation: ( )eY Y P P SRAS
1 1eP P
SRAS2
AD1
AD22eP
2P3 3
eP P
P e rritet, SRAS zhvendoset lart,dhe outputi vendoset ne nivelin natyror 1Y Y 2Y
3Y
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Chapter summaryChapter summary
1. Three models of aggregate supply in the short run: sticky-wage model imperfect-information model sticky-price model
All three models imply that output rises above its natural rate when the price level falls below the expected price level.
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 19
Chapter summaryChapter summary
2. Phillips curve derived from the SRAS curve states that inflation depends on
expected inflation cyclical unemployment supply shocks
presents policymakers with a short-run tradeoff between inflation and unemployment
CHAPTER 13CHAPTER 13 Aggregate Supply Aggregate Supply slide 20
Chapter summaryChapter summary
3. How people form expectations of inflation adaptive expectations
based on recently observed inflation
implies “inertia” rational expectations
based on all available information implies that disinflation may be
painless
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Chapter summaryChapter summary
4. The natural rate hypothesis and hysteresis the natural rate hypotheses
states that changes in aggregate demand can only affect output and employment in the short run
hysteresis states that agg. demand can have
permanent effects on output and employment
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