Transcript Chapter 12

Chapter 12
Economic
Fluctuations
Equilibrium
Inventory changes.
 Unintended changes in inventories
cause price levels and real outputs to
reach equilibrium.
 Two possibilities: the results of an
inventory increase and of an
inventory decrease.
An Economy in Equilibrium
Results of an Inventory Increase
Positive Unplanned Investment:
an unintended increase in inventories; a surplus
Results of an Inventory Decrease
Negative Unplanned Investment:
an unintended decrease in inventories; a shortage
The Role of Unplanned Investment
 Unplanned investment plays a central role in
stabilizing the economy, whether there is an inventory
increase or decrease.
 Unplanned investment is positive when the price level
is above its equilibrium value and negative when the price
level is below its equilibrium value, and in each case
unplanned investment is identical to the discrepancy
between aggregate demand and aggregate supply.
Injections and Withdrawals
Injections: additions to an economy’s income-spending
stream
i.
Investment (I)
ii.
Government purchases (G)
iii.
Exports (X)
Withdrawals: deductions from an economy’s incomespending stream.
i.
Saving (S)
ii.
Taxes (T)
iii.
Imports (M)
Investment and Saving
There are 3 reasons the amount saved and
the amount invested in an economy is not
equal:
1) companies keep a portion of their profits to
reinvest
2) governments also borrow money
3) foreign funds
Government Purchases and Taxes
If government purchases exceed taxes:
governments will borrow funds in financial
markets
If taxes exceed government purchases:
governments can use their excess revenues to pay
off some of their outstanding debt.
Exports and Imports
 imports were greater than exports from 1989
to 1993
 that means Canadians are spending more on
foreign goods than they receive revenue from
selling products to foreigners.
Total Injections and Withdrawals
 comparing these two provides a way of
explaining macroeconomic equilibrium that
complements the approach using aggregate
demand and aggregate supply.
 total injections = ( I + G + T )
 total withdrawals = ( S + T + M )
Expanding economy: total injections > total
withdrawals
 flows into the income-spending stream
falls are less than output
 the income-spending stream falls and slows
down
Contracting economy: total withdrawals > total
injections
 flows into the income-spending stream are
less than outflows
 the income-spending stream falls and slows
down
Equilibrium: total injections = total withdrawals
 inward and outward flows match, the incomespending stream circulates at a steady rate, so
that real output and spending in the economy
stay constant
Equilibrium With Injections and Withdrawals
An Economy at Its Potential Output
Equilibrium Vs. Potential Output
 it is possible for equilibrium to occur at the
economy’s potential output. In this case, actual
unemployment equals the natural unemployment
rate
Recessionary Gaps
 an economy’s real output rarely equals its
potential output.
 if equilibrium output is below its potential level,
unemployment is above the natural unemployment
rate.
 recessionary gap: the difference between
equilibrium output and potential output
Inflationary Gaps
 if equilibrium output is above its potential
output, unemployment is temporarily below
the natural unemployment rate.
 inflation will accelerate if this situation
persists.
 Inflationary Gap: when equilibrium
output exceeds potential output
Recessionary and Inflationary Gaps
John Maynard Keynes and the Transformation of
Macroeconomics
•John Maynard Keynes (1883-1946)
•His father was an economist and his mother was a
city politician.
•Studied mathematics at Cambridge University
•Published The General Theory of Employment,
Interest, and Money.
•During the Depression, Keynes and his followers
were able to convince most politicians and
economists that government intervention with a
coherent theory, which stressed the role-played by
aggregate demand in determing output in the
macroeconomic,.
•Keynesian ideas dominated macroeconomics
Neoclassical Theory
• Prior to Keynes, most economists
believe
that economic slowdowns
are self-correcting, this is referred to as
the
neoclassical theory.
• Two major assumptions: flexible labour
markets and Say’s Law.
Flexible Labour Markets
The demand and supply of labour depend
the real wage rate, or wages expressed in
constant basted-year dollars, rather than
the nominal wage rate,
which
is
valued in current dollars.

Both workers and employers adjust their
behavior only when the purchasing power
of
wages changes.

Employers demand less labour at higher
real wage
rates, while workers choose to
supply
more.

on
•Voluntary unemployment: when workers
decide that real wages are not high enough
to make work worthwhile.
•Involuntary unemployment: when someone
wants to work at the current real wage rate
but cannot
find a job.
•Involuntary unemployment occurs when
market demand and supply create a surplus,
and as long as labour markets are flexible,
the market forces of demand and supply
eradicate the surplus.
A Flexible Labour Market
Say’s Law

First outlined by a French
economist
JeanBaptiste Say.

Using the circular flow of money in
the economy, Say argued that supply
automatically creates its own
demand.
Keynesian Theory
•
Keynes challenged both of the
assumptions of neoclassical
economics.
•
A theory that explained how
involuntary
unemployment and under
spending had become chronic
problems during the Depression
Challenge to Flexible Labour Markets
Keynes believed workers were
influenced
by money illusion.

Workers would respond to changes
in
nominal wages, rather than real
wages
and purchasing power.

Challenge to Say’s Law
•
•
Keynes proved Say’s Law is only valid if all income in
an economy is spent.
According to the law, reduced spending is only
temporary; total expenditures and production soon
balance each other out. This occurs since total
withdrawals and injections can be equal at any
output.
•
Interest rates charged in financial markets will vary
until
withdrawals leaving the circular flow are matched
by
injections.
•
However, Keynes proved that output levels, not
interest
rates, adjust to bring about a balance
between total injections and withdrawals.
•
Say’s Law is only true when injections are less than
withdrawals, output falls until a new equilibrium level
is reached, and it is only at this equilibrium that this
law is true.
An Inflexible Labour Market