Download presentation
Presentation is loading. Please wait.
Published byJohn Turner Modified over 9 years ago
1
Chapter 5
2
Phillips curve : shows the short-run trade-off between inflation and unemployment 1958: A.W. Phillips showed that nominal wage growth was negatively correlated with unemployment in the U.K. 1960: Paul Samuelson & Robert Solow found a negative correlation between U.S. inflation & unemployment, named it “the Phillips Curve.”
3
“The Phillips curve shows the combinations of inflation and unemployment that arise in the short run as shifts in the aggregate-demand curve move the economy along the short-run aggregate supply curve” (803).
4
PL=100 in 2020 Two outcomes are possible in 2021 If AD is high… PL rises by a lot (output increases substantially) (B) If AD is low… PL rises by a little (output increases slightly) (A) Y P SRAS AD 1 AD 2 Y1Y1 103 A 105 Y2Y2 B u-rate inflatio n PC 6% 3% A 4% 5% B
5
Both graphs are connected As “A” moves to “B” the output increases Higher output= higher demand for workers Higher demand for workers= lower unemployment As “A” moves to “B” the PL increases Increasing the PL increases the rate of Inflation
6
Fiscal and monetary policies affect the AD; therefore, the PC offers policymakers a menu of choices: low unemployment with high inflation low inflation with high unemployment anything in between
7
Natural-rate hypothesis : the claim that unemployment eventually returns to its normal or “natural” rate, regardless of the inflation rate Based on the classical dichotomy and the vertical LRAS curve
8
Y P LRAS AD 1 AD 2 Natural rate of output P1P1 P2P2 u-rate Inflatio n Natural rate of unemployment LRPC low inflatio n high inflation
9
Since the LRAS curve is vertical, and output stays constant, any increase in AD just increases Inflation.
10
Expected Inflation: Measure of how much people expect the overall PL to change
11
Unemployment Rate (UR) Natural Rate of Unemployment (NRU) Actual Inflation (AI) Expected Inflation (EI) UR= NRU+ a(AI – EI) a= in a parameter of how much unemployment responds to unexpected inflation
12
Short run Fed can reduce u-rate below the natural u-rate by making inflation greater than expected. Long run Expectations catch up to reality, u-rate goes back to natural u-rate whether inflation is high or low.
13
Natural-Rate Hypothesis: Claims that unemployment eventually returns to its normal, or natural, rate, regardless of the rate of inflation
14
Supply shock : an event that directly alters firms’ costs and prices, shifting the AS and PC curves Example: large increase in oil prices
15
Y P SRAS 1 ADAD SRAS 2 A Y1Y1 P1P1 Y2Y2 B P2P2 U-Rate Inflatio n PC 1 PC 2 A B
16
SRAS Curve shifts left: Output decreases Price level increases Unemployment rises
17
Sacrifice Ratio: The number or % points of annual output lost in the process of reducing inflation by 1% point Rational Expectations: The theory that people optimally use all the information they have including information about gov.t policies, when forecasting the future
18
Typical estimate of the sacrifice ratio: 5 To reduce inflation rate 1%, must sacrifice 5% of a year’s output. Can spread cost over time, e.g. To reduce inflation by 6%, can either sacrifice 30% of GDP for one year sacrifice 10% of GDP for three years
19
Ex. Fed claims that they’re going to reduce inflation Expected Inflation decreases (SRPC shifts downward) Result: Disinflations can cause less unemployment that the traditional sacrifice ratio predicts.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.