Unit 5 and 6
AD/AS From Short Runt to Long Run
- AS curve doesn't shift in response to changes in the AD curve in the short run
- i.e. - Nominal Wages do not respond to price level changes
- workers may not realize impact of the changes or may be under contract
- Long run- Period in which nominal wages are fully responsive to previous changes in the price level
- When changes occur in the short run they result in either increased or decreased produce profits not changes wages
- In the long run increases in AD result in a higher price level, as in the short run, but as workers demand more money the AS curve shifts left to equate production at the original output level, but now at a higher price
- In the long run, the AS curve is vertical at the natural rate of unemployment(NRU), or full employment(FE) level of output. Everyone who wants a job has one and no one is enticed into or out of the market
- Demand-pull Inflation will result when an increase in the demand shifts the AD curve to the right temporarily increasing output while raising prices
- Cost-push Inflation results when an increase in input costs that shifts the AS curve to the left. In this case the price level increase in not in response to the increase in Ad, but instead the cause of price level increasing.
Phillips' Curve
- Represents the relationship between unemployment and inflation
- Trade off between inflation and unemployment only occurs in the short run
- Each point on PC corresponds to a different level of output
- LRPC- occurs at the natural rate of unemployment, vertical line there is no trade off between unemployment and inflation in the long run
- economy produces at the full employment output level
- Nominal wages of workers full incorporate any changes in PL as wages adjust to inflation over the long run
- LRPC will only shift if LRAS shifts
- Increases in unemployment shifts LRPC to the right
- Decreases in unemployment shifts LRPC to the left
Types of Unemployment
- Frictional
- Structural
- Seasonal
Short run Phillips curve
- PC stable in short run, because SRAS curve is stable
Supply Shock
- Rapid and significant increases in resource costs which causes the SRAS curve to shift thus producing a corresponding shift in the SRPC curve.
Misery Index
- combo of inflation and unemployment in any given year
- single digit misery is good
Stagflation
- occurs when you have high unemployment and high inflation occurring at the same time
Disinflation
- when inflation decreases overtime
Supply-side economics (Reaganomics)
- Support policies that promote GDP growth by arguing that high marginal tax rates along with the current system of transferred payments such as unemployment and social security payments provide disincentives to work, invest, innovate, and undertake entrepreneurial ventures.
- Economists tend to believe that the AS curve shifts to the right thus creating the trickle-down effect.
Marginal tax rates
- amount paid on last dollar earned or on each additional dollar earned
- by reducing the marginal tax rates supply-siders believe that you will encourage more people to work longer foregoing leisure time for extra income
Laffer Curve
- trade offs between tax rates and tax revenues
- Criticisms
- Where the economy is actually located on the curve is difficult to determine.
- Tax cuts also increase demand, which can fuel inflation.
- Empirical evidence suggests that the impact of tax rates on incentives to work, invest, and save are small.
- The higher the tax rate you set, the less money you will collect.
- Laffer curve is controversial and debatable.
Economic Growth
Defined
•
Sustained
increase in Real GDP over time.
•
Sustained
increase in Real GDP per Capita over time.
Why Grow?
•
Growth
leads to greater prosperity for society.
•
Lessens
the burden of scarcity.
•
Increases
the general level of well-being.
Conditions for
Growth
•
Rule of
Law
•
Sound
Legal and Economic Institutions
•
Economic
Freedom
•
Respect
for Private Property
•
Political
& Economic Stability
–
Low
Inflationary Expectations
•
Willingness
to sacrifice current consumption in order to grow
•
Saving
•
Trade
Physical Capital
•
Tools,
machinery, factories, infrastructure
•
Physical
Capital is the product of Investment.
•
Investment
is sensitive to interest rates and expected rates of return.
•
It takes
capital to make capital.
•
Capital
must be maintained.
Technology & Productivity
•
Research
and development, innovation and invention yield increases in available
technology.
•
More
technology in the hands of workers increases productivity.
•
Productivity
is output per worker.
•
More
Productivity = Economic Growth.
Human Capital
•
People
are a country’s most important resource. Therefore human capital must be
developed.
•
Education
•
Economic
Freedom
•
The
right to acquire private property
•
Incentives
•
Clean
Water
•
Stable
Food Supply
•
Access
to technology
Hindrances to Growth
•
Economic
and Political Instability
–
High
inflationary expectations
•
Absence
of the rule of law
•
Diminished
Private Property Rights
•
Negative
Incentives
–
The
welfare state
•
Lack of
Savings
•
Excess
current consumption
•
Failure
to maintain existing capital
•
Crowding
Out of Investment
–
Government
deficits & debt increasing long term interest rates!
•
Increased
income inequality à Populist policies
•
Restrictions
on Free International Trade
The Phillips Curve
•
In a
1958 paper, New Zealand born economist, A.W. Phillips published the results of
his research on the historical relationship between the unemployment rate (u%)
and the rate of inflation (π%) in Great Britain. His research indicated a
stable inverse relationship between the u% and the π%. As u%↓, π%↑ ; and as
u%↑, π%↓. The implication of this relationship was that policy makers could
exploit the trade-off and reduce u% at the cost of increased π%. The Phillips
curve was used as a rationale for the Keynesian aggregate demand policies of
the mid-20th century.
Trouble for the
Phillips Curve
•
In the
1970’s the United States experienced concurrent high u% & π%, a condition
known as stagflation. 1976 American Nobel Prize economist Milton Friedman saw
stagflation as disproof of the stable Phillips Curve. Instead of a trade-off
between u% & π%, Friedman and 2006 Nobel Prize recipient Edmund Phelps
believed that the natural u% was independent of the π%. This independent
relationship is now referred to as the Long-Run Phillips Curve. I believe it’s
relevant that by this time the Bretton-Woods system had collapsed.
The Long-Run
Phillips Curve (LRPC)
•
Because
the Long-Run Phillips Curve exists at the natural rate of unemployment (un),
structural changes in the economy that affect un will also cause the
LRPC to shift.
•
Increases
in un will shift LRPC à
•
Decreases
in un will shift LRPC ß
The Short-Run
Phillips Curve (SRPC)
•
Today
many economists reject the concept of a stable Phillips curve, but accept that
there may be a short-term trade-off between u% & π% given stable inflation
expectations. Most believe that in the long-run u% & π% are independent at
the natural rate of unemployment. Modern analysis shows that the SRPC may shift
left or right. The key to understanding shifts in the Phillips curve is
inflationary expectations!
Relating Phillips
Curve to AS/AD
•
Changes
in the AS/AD model can also be seen in the Phillips Curves
•
An easy
way to understand how changes in the AS/AD model affect the Phillips Curve is
to think of the two sets of graphs as mirror images.
•
NOTE:
The 2 models are not equivalent. The AS/AD model is static, but the Phillips
Curve includes change over time. Whereas AS/AD shows one time changes in the
price-level as inflation or deflation, The Phillips curve illustrates
continuous change in the price-level as either increased inflation or
disinflation.
Summary
•
There is
a short-run trade off between u% & π%. This is referred to as a short-run
Phillips Curve (SRPC)
•
In the
long-run, no trade-off exists between u% & π%. This is referred to as the
long-run Phillips Curve (LRPC)
•
The LRPC
exists at the natural rate of unemployment (un).
–
un ↑
.: LRPC à
–
un
↓ .: LRPC ß
•
ΔC, ΔIG,
ΔG, and/or ΔXN = Δ AD = Δ along SRPC
–
AD à .: GDPR↑ & PL↑ .: u%↓ & π%↑ .: up/left along SRPC
–
AD ß .: GDPR↓ & PL↓ .: u%↑ & π%↓ .: down/right along SRPC
•
Δ
Inflationary Expectations, Δ Input Prices, Δ Productivity, Δ Business Taxes
and/or Δ Regulation = Δ SRAS = Δ SRPC
–
SRAS à .: GDPR↑ & PL↓ .: u%↓ & π%↓ .: SRPC ß
–
SRAS ß .: GDPR↓ & PL ↑ .: u%↑ & π%↑.: SRPC à
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