Economics test.
Policy Interventions
ISLM-ASAD Full Model
Remember key equations
IS: Y = C + I + G + NX
LM: MS/P = L (r, Y)
AD: Combine IS + LM
LRAS: Yn = A x F (K, L, N, H)
SRAS: Y = Yn + z (P – Pe)
C = C0 + m (Y – T)
I = I0 – j x r
Monetary Policy
Stimulus / Boost GDP
Increase money supply
Example: Buy bonds
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*=Y-L
SRAS
LRAS
AD
Y*=Y-L
LM2
AD2
Ps
Ys
Ys
LMs
rs
P
r
P
Y
Y
LM
IS
r*=r-L
P*=Pe*
Y*=Yn*=Y-L
SRAS
LRAS
AD
Y*=Y-L
LM2
AD2
Ps
Ys
Ys
LMs
rs
SRAS-L
P
P-L=Pe-L
LM-L
Fiscal Policy
Stimulus / Boost GDP
Increase government spending OR
Cut taxes
Goal: Raise GDP, lower unemployment
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
IS2
AD2
rs
Ps
Ys
LMS
Y*
Ys
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*=YL
SRAS
LRAS
AD
IS2
AD2
rs
Ps
Ys
SRASL
LMS
LML
Y*=YL
rL
PL =Pe-L
Ys
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*=YL
SRAS
LRAS
AD
IS2
AD2
rs
Ps
Ys
SRASL
LMS
LML
Y*=YL
rL
PL =Pe-L
Ys
r
P
Y
Y
LM
IS
r*=r-L
P*=Pe*
Y*=Yn*=Y-L
SRAS
LRAS
AD
Y*=Y-L
LM2
AD2
Ps
Ys
Ys
LMs
rs
SRAS-L
P
P-L=Pe-L
LM-L
Monetary Policy
Fight inflation
Lower money supply
Example: Sell bonds
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
LM2
AD2
rs
Ps
Ys
LMS
Y*
Ys
r
P
Y
Y
LM = LML
IS
r* = rL
P*=Pe*
Y*=Yn*=YL
SRAS
LRAS
AD
LM2
AD2
rs
Ps
Ys
SRASL
LMS
Y*=YL
PL =Pe-L
Ys
Federal Reserve Dual Mandate
Stabilize prices
Maximize employment
Policy tools:
Buy/sell bonds
Raise/lower discount rate
Etc.
NOT: Change gov’t spending or taxes
Problem: Stock market crash
Wealth falls, so C0 drops
First: Show what happens in the short run with no intervention
What is our policy recommendation?
- BUY BONDS
Then, show the short run and long run outcome of the initial problem COMBINED with our intervention
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
IS2
AD2
rs
Ps
Ys
LMS
Y*
Ys
r
P
Y
Y
LM
IS
r*
P*=Pe*=Ps=PL
Y*=Yn*=Ys =YL
SRAS
LRAS
AD = ADReact
IS2
AD2
rs
Y*
Ys
LMReact
Problem: We run out of oil
Fall in our supply of natural resources.
Show the short-run problem
Make a policy recommendation (For the Fed)
Show the short run and long run outcome of your recommendation
Federal Reserve Dual Mandate
Stabilize prices
Maximize employment
Policy tools:
Buy/sell bonds
Raise/lower discount rate
Etc.
NOT: Change gov’t spending or taxes
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
LRAS2
SRAS2
Ps
rs
Ys
LMS
Ys
YL=YnL
Option 1: Do Nothing
r
P
Y
Y
LM
IS
r*
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
LRAS2
SRAS2
Ps
rs
Ys
LMS
Ys
SRASL
LML
rL
PL =Pe-L
YL=YnL
YL
Option 1: Do Nothing
Short run: Inflation, recession, high unemployment
Long run:
Even worse inflation, even worse recession, even worse unemployment
You’re fired.
Option 2: Stimulus
Buy bonds
Bring GDP back to initial level
r
P
Y
Y
LM = LMs
IS
r* = rs
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
LRAS2
SRAS2
Ps
Ys
LMReact
Ys
AD2
r
P
Y
Y
LM = LMs
IS
r* = rs
P*=Pe*
Y*=Yn*
SRAS
LRAS
AD
Y*
LRAS2
SRAS2
Ps
Ys
LMReact
Ys
YL=YnL
AD2
SRASL
PL =Pe-L
rL
LML
Option 2: Stimulus
Short run: No recession! But massive Inflation
Long run:
Crushing inflation, even worse recession, even worse unemployment
You’re fired. But you might have kept your job for a year or two first.
Option 2: Contraction
Sell bonds
Stabilize prices
r
P
Y
Y
LM = LMs
IS
r*
Y*=Yn*
SRAS
LRAS
AD
Y*
LRAS2
SRAS2
Ys
LMReact
Ys
YL=YnL
AD2
rs = rL
P*=Pe*=Ps=PL
Option 2: Contraction
Short run: Deep recession right away, but inflation controlled
Long run:
Stable prices, no further changes
Outcome: You’re probably fired, but you did your job
General rule
Stabilize prices first.
We solve this in reverse (start at the end and work backwards):
Move AD so it crosses LRAS at the current price level
To do that, move LM so it crosses IS at the same Y as your target for AD
Then find short run and long run outcomes