Edward
Shapiro
MACROECONOMIC ANALYSIS
Chapter 17: The Classical Theory
Index THE CLASSICAL THEORY The Level of Output and
Employment in Classical Theory Say’s
Law The Quantity Theory of
Money
The Quantity Theory as a Theory of the Price
Level The Quantity Theory as a Theory of Aggregate Demand Web 3
Classical Model without
Saving and Investment
Effects of a Change in the Supply of Money
Effect of a Change in the Supply of Labor
Effects of a Change in the Demand for Labor Monetary Policy and Full Employment Classical Model with Saving
and Investment
Saving and Investment
Changes in Saving and Investment Summary
Statement |
CLASSICAL MODEL WITHOUT
SAVING AND INVESTMENT
Previously, the level of
employment was shown to be determined by the supply of and demand for labor; the
level of output (with a given production function) was shown to be determined by
the level of employment; and the level of prices was shown to be determined by
the supply of money. Figure 17-2
illustrates the interrelationships of the variables in this classical
model.
In Part B, the intersection
of the two curves defines the point of full employment, N1,
and the real wage, (W/P)1, necessary to achieve full
employment. With this real wage in
effect, employment is N1, which defines full-employment
output, O1, in Part A. The price level of output depends on M
and V, and the curve M1V specifies a particular
money supply and some constant velocity of money. From
(or from),
once M, V, and O
are known, the price level is also known. 11 In this case, given M, V and
O1, the price level is
P1.
Part D of Figure 17-2 is
new; it shows the money-wage adjustment necessary to establish equilibrium.
In Part B (W/P)1
is consistent with any number of pairs of values for W and
P, and these possible pairs of values, when plotted, trace the
upward-sloping straight line labeled (W/P), in Part D. For a real wage higher than
(W/P)1 the slope of the line in Part D would be steeper and
would thus combine a higher W with each P or a lower
P with each W. For a real wage lower than
(W/P)1, the slope of the line in Part D would be flatter and
would thus combine a lower W with each P or a higher
P with each W. Only one money wage will produce the
real wage (W/P)1, indicated by the slope of the line in Part
D, at the given price level. With
the price level P1 established in Part C, the required
money wage is accordingly established in Part D as W1. If the actual money wage in the
market is higher than W1 - the money wage now identified as that
required for full employment - then the resulting unemployment and competition
among workers for jobs will force the money wage to drop until the system
regains its full-employment equilibrium
position.
The interconnected parts of
Figure 17-2 thus enable us to identify the full set of equilibrium values for
this simple classical system: employment N1, output
O1, price level P1, and money wage
W1. Barring any
shift in the production function or the supply curve of labor or any change in
the money supply or its velocity, the indicated set of equilibrium values will
remain unchanged period after period, in practice, of course, these elements
will change over time, but
11. We may now change
to MV = PO, using the equality
sign instead of the identity sign.
We now have an equation that sets forth the condition fro
equilibrium. With MV and
O, equilibrium P is that P at which P =
MV/O.
348
for each change, under
classical assumptions, new equilibrium values will be established for the
variables of the system. Tracing
through several such changes will illustrate the mechanics of the
system.
Effects of a Change in the
Supply of Money
Consider first the case of
an increase in the money supply as indicated by the shift of the MV curve
from M1V to M2V in Figure 1 7-2C. The increase in M (with constant
V) means an increase in total spending per time period of
V(M2- M1) and a rise in the
price level from P1 to P2 for the output
level 01. If the
money wage does not rise proportionately with this rise in the price level, the
real wage will fall, causing employers to try to expand output by hiring more
workers, for a higher price for output without a higher money wage rate means
greater profits with greater output. But a real wage below
(W/P)1 means that the quantity of labor available is too small
to produce output O1 let alone to expand output beyond this.
Competition among employers for
workers will then force the money wage up until it rises proportionately with
the price level, leaving the equilibrium real wage unchanged at
(W/P)1 and the profit-maximizing output unchanged at
O1. The net
result of the expansion of the money supply is a proportionate rise in the price
level and in the money wage but no change in employment or output; the new
equilibrium values are N1, 01, P2,
and W2.
This, of course, is just
what we should expect on quantity theory reasoning. The level of output is determined by the
real factors of labor productivity and the quantity of labor employed; the money
supply only sets the price level for this output. Increasing or decreasing the money supply
will cause the price level of output to rise or fall proportionately, but the
level of output itself will remain unchanged. Any change in the money supply that is
accompanied by a change in the velocity of money will break the proportionate
relationship between M and P but will still leave the level
of output and employment unaffected by changes in either M or
V.
Effects of a Change in the
Supply of Labor
Now let us imagine an
increase in the labor supply, as shown by the shift from SL to
S’L in Figure 17-3. With no shift in the production function
and so no shift in the curve of the MPP of labor, any increase in employment
will lower the MPP of labor. The
full-employment equilibrium previously was at N1, with the MPP of labor
or the real wage (W/P)1. If there is to be full employment,
the real wage must now fall from (W/P)1 to
(W/P)2 for only at (W/P)2 does the supply of
labor equal the demand for labor. A
fall in W/P is expected in classical theory under the pressure of
unemployment now present at the real wage of (W/P)1;
competition among workers for jobs gradually forces down the money wage,
and a drop in the money wage with no drop in the price
level
The present construction
enables us to face a complication earlier side-stepped - the fact that a drop in
the money wage must lead to a drop in the price level, with a given money supply
and constant velocity. As the money
wage falls below W1, firms expand employment beyond
N1, which raises output beyond O1. When MV is unchanged,
aggregate demand is unchanged. To
provide a market for enlarged output requires a fall in the price level. (From
MV =
350
sell the expanded output of
O2 with aggregate demand unchanged at MV in Part
C.
A numerical “before” and
“after” example may clarify the adjustments involved. The first row of the table below gives
the equilibrium values for N, O, W, and P when labor demand is
DL, labor supply is SL (Figure 17-3), the money
supply is $75, and velocity is 4. The second row gives the new equilibrium
values after the shift in SL to S’L. Full employment now calls for N
of 150, at which level the MPP of labor is 1.66. If there is to be full employment, the
real wage must fall from 2 to 1.66. Suppose that in the face of unemployment
the money wage falls to $1.66. If
P stayed at 1, this would reduce the real wage to $1.66/l, or 1.66, the
value required for full employment. At this real wage, N is 150 and
O is 400. But output of 400
cannot be sold at a price level of 1, since aggregate demand is MV of
$300. Therefore P must fall,
but any fall in P raises the real wage and causes a contraction in N.
Any unemployment must lead to a
further fall in W, which in turn calls for a further fall in P. In this fashion, through successive
adjustments, the process finally ends with the consistent set of values in the
second row below. 12
Given an increase in the
labor supply, the crucial element of the process by which the system moves to
its new equilibrium position is the adjustments that occur in the money wage and
the price level. Whether
unemployment threatens from an increase in the labor supply or for other
reasons, flexibility of the money wage and price level is indispensable to the
correction of unemployment. As long
as the money wage responds to unemployment and as long as the price level
responds to changes in output, full employment can always be regained according
to this simple classical model.
12. On the
assumption of profit maximization, employers will not expand employment unless
greater profits are expected from the sale of the higher level of output. In this case, there will be greater
profits, as may be seen from the figures. At the original equilibrium, labor’s
share of the real output of 300 is N x MPP, or 100 x 2, or 200. The remainder, O - (N x
MPP), or 100, may be called the “profit share.” At the new equilibrium, labor’s share of
the real output of 400 is 150 x 1.66, or 250, leaving 150 as the “profit share,”
an increase in profits of 50. In dollar terms, the flow of
income at the original equilibrium is $300, or 300 x 1, divided into $200
for labor and $100 for profits. At
the new equilibrium, it is the same $300, or 400 x 0.75, now divided into
$187.50, or 150 x $1.25 for labor and $112.50 for profits. Though labor’s share is decreased in
money terms from $200 to $187.50, the $187.50 adjusted for the fall in P
from 1 to 0.75 is equal to $250 in “base period” prices. Similarly, the profits of $112.50 are
equal to $150 in “base period” prices.
351
Effects of a Change in the
Demand for Labor
Growth in the capital stock
or technological advances will cause the production function to shift upward
over time, as shown by the movement from O to O’ in Figure l7-4A.
At each possible level of
employment, the MPP of labor is now greater than it was, since at each level of
N the slope of O’ exceeds the slope of O. This is reflected in Figure 17-4B as
an upward or right-ward shift in the demand curve for labor, indicating that it
is now profitable for employers to hire more labor at each possible real wage.
The equilibrium real wage rises
from (W/P)1 to (W/P)2; employment rises from
N1 to N2 and output rises from
O1 to O2. With no change in the money supply,
the greater output requires a fall in the price level from P1
to P2. At the
new equilibrium real wage of (W/P)2, price level P2
calls for money wage W2. In the present case, the rise in the
real wage necessary to reestablish equilibrium is produced by a fall in P
and a rise in W.
The first row of the
following table repeats the set of figures previously used to describe the
original equilibrium values; the second row gives a set
of
352
In passing, we may note
several basic propositions in economics that are clearly brought out by the
present analysis. For one, the
gradual rise in the real wage, or “standard of living” of labor, is primarily
the result of the gradual upward shift in the production function, which is
largely attributable to technological progress and a growing stock of capital.
If, over the same period in which
these developments raised the schedule of marginal productivity of labor from
DL to D’L, the supply curve of labor had
also moved from SL to S’L, the number of workers
employed would have risen, but the real wage would have remained the same. The actual gradual rise in the real wage
experienced over the long run in Western economies has resulted primarily from
the fact that the growth in capital and the rate of technological advance have
exceeded the rate of growth in the labor force.
A second proposition
brought out by this analysis is that the long-run growth of output (whether
produced as here by an upward shift in the production function, or as in the
previous case by a shift to the right in the labor supply curve, or as in
practice by both) leads to a falling price level unless accompanied by an
expansion in the money supply. Although an expansion of output with no
rise in the money supply will in practice cause V to rise, V
cannot rise without limit. Therefore, as output expands in the long
run, M must expand to avoid what otherwise must be a gradually falling
P. Although these
propositions have been brought out by the classical model, they are accepted in
principle by most economists today.
From an initial equilibrium
with given MV, an increase in the supply of labor calls for a fall in the
money wage and a lesser fall in the price level to establish a new
full-employment equilibrium at a lower real wage. Classical theory assumes perfectly
competitive markets, and an excess supply of labor in such markets will
automatically depress the money wage. If we now drop the assumption of perfect
competition in the labor market, the results may be different. Consider, for example, the imperfection
of competition that results when workers are organized into, labor unions. There will be no barrier to a rise in the
money wage when excess demand for labor appears, but there will now be a barrier
to a fall in the money wage when excess supply
appears.
353
In other words, the money
wage is flexible upward but may be rigid downward. Furthermore, in an imperfect market the
money wage may be forced up even though there is no excess demand for labor.
To illustrate, let us begin with a
full-employment equilibrium position for the economy and observe the effect of a
money wage that is arbitrarily pushed up, say by union
pressure.
In Figure 17-5 there is
full-employment equilibrium with a real wage of (W/P)1 and
values for other variables indicated by subscript 1. Suppose now that the money wage is forced
up from W1 to W2. If the price level were to remain at
P1, a rise in the real wage would occur proportionate to the
rise in the money wage. But, with
the given M and V, the price level must rise; for in the absence
of a rise in P there is a rise in the real wage, which means a decrease
in O, and, with aggregate demand given by MV, a lower O
means a higher P. While P
must therefore rise, it cannot, however, rise as far as W, for if it
did there would be no change in the real wage and so no change in output. The original output cannot all be sold
with unchanged aggregate demand of MV at a higher P, so P
must rise in proportion to the fall in
O.
The process by which a new
equilibrium is reached is one in which P. 0, and N must all adjust
to the rigidly fixed money wage W2. The new equilibrium values for P,
O, and N are designated by the subscript 2. As compared to the initial equilibrium
there are now a higher real wage, a lower output level,
and
355
a higher price level. The higher real wage, which was
artificially brought about by forcing up the money wage, forces employment down
from N1 to N2. Since the amount of labor supplied is
greater with a higher real wage, the amount of unemployment is not merely the
difference between N1 and N2, but is the
larger difference between N3 and N1. With the higher real wage, those
workers fortunate enough to keep their jobs are, of course, better off than they
were before the rise in the money wage.
To illustrate this
situation, a numerical example follows similar to those given earlier. Since the new equilibrium is not one of
full employment, the last three columns have been added to show the resulting
unemployment. (S is labor supplied; D is labor demanded; U is
labor unemployed.)
With full-employment
equilibrium defined by a real wage of 2, we can see from the figures that
unemployment must result from the arbitrary raising of the money wage from $2.00
to $2.40.
As long as the money wage
is arbitrarily held above the level consistent with full employment, we have an
equilibrium situation with unemployment. Although we have noted several times
before that classical theory denied this possibility of equilibrium with
unemployment, the denial was made only on the assumption that we were dealing
with an economy in which the money wage was flexible. Underemployment equilibrium is therefore
entirely consistent with classical theory when that theory is stripped of the
assumption of flexible wage rates, an assumption indispensable to its
full-employment conclusion.
In the General Theory,
Keynes replaced the classical assumption of a flexible money wage with that
of a rigid money wage, an assumption certainly more closely in agreement with
the facts of observation. In so
doing, Keynes could easily enough show that equilibrium with unemployment is
possible. Though a great deal more
is involved, what should be clear from analysis of the present case is that the
corresponding change in assumption in the classical theory leads to the same
possibility of underemployment equilibrium reached by Keynes in the General
Theory.
Monetary Policy and Full
Employment
In the classical scheme, if
the money wage is held artificially above the level necessary for full
employment, an appropriate expansion of the money supply may be an
antidote. According to quantity
theory, an increase in M
355
with V and O
stable, will raise P proportionately. With a rigid money wage, the rise in P
reduces the real wage and provides the profit incentive to employers to
expand employment and output toward the full-employment level. There is, therefore, some appropriate
expansion in the money supply that is sufficient first to raise P to the
level that reduces the real wage, W/P, to the full-employment equilibrium
level and second to purchase the full-employment output that
results.
In terms of Figure 17-5D,
to achieve the full-employment real wage of (W/P)1 with the
money wage inflexible at W2 requires a price level of
P3, since at that level W2/P3,
equals W1/P1 or (W/P)1. With real wage of
(W/P)1, output is O1. Therefore, in Part C, MV must
be increased to equality with P3O1 to generate
demand adequate to purchase full-employment output O1 at price
level P3. 13
The previous numerical
example may be modified to show how an appropriately expansionary monetary
policy may offset the effect of a rigid money wage. The first two rows of the following table
are the same as before - the first describes the initial full-employment
equilibrium, the second the underemployment equilibrium that results from a
money wage artificially pushed up. The third row shows the return to a
full-employment equilibrium that results from the appropriate expansion of
M.
Note that the strict
quantity theory does not hold because part of the additional demand created by
the expansion of M is absorbed by the expansion of output that
accompanies the fall in the real wage. M rises from $75 to $90, or by 20
percent; P rises from 1.10 to 1.20, or by less than 10
percent.
Thus, it would seem that
monetary policy provides the solution to unemployment created by a rigid money
wage. But it is equally apparent
from the crude model before us that this method of securing full employment in
the face of artificially high wage rate works only as long as the increase in
M is not offset by a decrease in V. Aggregate demand must increase with
the increase in M. Classical
theory saw no “leakage” between an increase in M and an increase in
aggregate demand. We can begin to
see why monetary policy was the policy weapon of classical economists.
When we return in the next chapter
to Keynesian theory, we will see that this simple tie between changes in the
money supply and
13. With V constant,
356
changes in aggregate demand
disappears. In Keynesian theory,
aggregate demand cannot be so simply increased or decreased by expansion or
contraction of the money supply.