Download - Diagrams
Semester Two DiagramsTomoyo Joshi
Average Price Level
Real Output = National Income = Y
0
Aggregate Demand Curve
The AD curve shows total demand in an economy,And thus output from households, firms,the government and the international sector at difference price levels. A fall in prices from PL1 toPL2 leads to an increase in real output from Y1 to Y2.
AD = C+I+G+[X-M]
Y1 Y2
P1
P2
C = Consumption I = Investments G = Government Spending X = Exports M = Imports
Average Price Level ($)
Real Output (Y)0
SRAS
Y1 Y2
P1
P2
Short-Run Aggregate Supply (SRAS) Curve
In the short run, increases in output will normally onlybe achieved in increases in average costs. These are passed onto the consumers through higher prices. So an increase in output from Y1 to Y2 will only be achieved with an increase in prices from P1 to P2.
Average Price Level ($)
Real Output (Y)
0
(1)
(2)
(3)
LRAS
Y1
Keynesian Long-Run Aggregate Supply Curve
1. Output maybe increased with no increase in prices, because there is lots of spare capacity in the economy.
2. Spare capacity is being used up and output goes up, but with increases in costs as factors of production cost more
3. Output cannot be increased because all factors are being used.
AveragePrice Level ($)
0Real Output (Y)
P1
P2
Neo-Classical Long Run Average Supply (LRAS) Curve
Neo-Classical economists believe that the LRAS curve us set by quantity and quality of factors of production in the economy and so it is perfectly inelastic at the full employment level of output (Y1)
Y1
AveragePrice Level ($)
0Real Output (Y)
SRAS
AD
Short-run Equilibrium Output
The economy is in short-run equilibrium where AD equals SRAS and so there will be an output level of Y at a price level of P.
P
Y
AveragePrice Level ($)
0Real Output (Y)
Expansionary Demand-Side Policy
AD1
AD2
P1
P2
Y1 Y2
A government may use fiscal and/or monetary policy to shift AD from AD1 to AD2. This would have an effect of expanding the economy from Y1 to Y2, thus increasing employment. However, there will be a “trade-off” as the price level rises from P1 to P2.
AveragePrice Level ($)
0Real Output (Y)
LRAS1 LRAS2
Y1 Y2
P1
P2
The Effect of Supply-Side Policies for Keynesian and Neo-Classical LRAS Curves
Both Keynesian and Neo-Classical economists believe that an improvement in the quantity and/or quality of factors of production will shift the LRAS curve to the right.
AveragePrice Level ($)
0Real Output (Y)
SRAS2
SRAS1
AD
P2
P1
Y1 Y2
Cost Push Inflation
When there is an increase in the costs of facts of production such as wage increases in oil prices, then firms’ costs are pushed upwards, the STAS curve shifts from SRAS1 to SRAS2, and the average price level rises from P1 to P2. This is cost-push inflation. Real output also falls from Y1 to Y2.
AveragePrice Level ($)
0Real Output (Y)
LRAS
AD
Y Y1
P
The Equilibrium Level and the Full Employment Level, of National Income
The long-run equilibrium level of national income is where AD is equal to LRAS. The full employment level of national income is where all factors are being employed. Keynesians believe that the two do no necessarily coincide. The equilibrium level is at Y, but the employment level is at Y1.
0
SR Phillips CurveIn
flati
on
ra
te (
%)
Unemployment Rate (%)
2
6
53
NRU
SRPC
0
LR Phillips Curve
Unemployment Rate(%)
A
B
C
D
SRPC1
SRPC2
SRPC3
LRPC
6
E
6
10
3
2
Infl
ati
on
ra
te (
%)
0
Perfectly Elastic SupplyP
rice
Quantity
D1 D2
SP1
Q1 Q2
0
An Inelastic Supply CurveP
rice
QuantityQ1
Q2
D1
D2
S
P1
P2
0
An Elastic Supply Curve
Pri
ce
QuantityQ1
Q2
D1
D2
S
P1
P2
0
An Perfectly Inelastic Supply Curve
Pri
ce
QuantityQ1
D1
D2
S
P2
P1
0
Negative Production ExternalityP
rice
Q opt.
MSC
P1
S=MPC=Sum of All Private Costs
Q1
D= Marginal Private Benefit
Welfare loss
Negative Externality
Quantity
0
Negative Consumption Externality
Pri
ce
Q opt.
MSB
P1
S=MPC=Sum of All Private Costs
Q1
D= Marginal Private Benefit
Negative Externality
Quantity
Welfare loss
0
Tax and Negative Production Externality
Pri
ce
MSC
P1
S=MPC=Sum of All Private Costs
Welfare loss
Tax
D= Marginal Private Benefit
Q1
P opt
Q opt
0
Tax on Producers and Negative Consumption Externality
Pri
ce
MSB
P1
S=MPC=Sum of All Private CostsTax
D= Marginal Private Benefit
Q1
P opt
Q opt
Quantity
0
Ave
rag
e (
real)
wag
e r
ag
e
Number of Workers
Real Wage Unemployment
ADL
AS L
Q1 Q2
W1
We
a b
0
Ave
rag
e (
real)
wag
e r
ag
e
Number of Workers
Demand Deficient Unemployment
ADL1
AS L
Q1 Qe
We
W1
ab
cADL