Title: X. Neoclassical synthesis
1X. Neoclassical synthesis
2X.1 Keynes vs. real world
3Keynes theory
- Macroeconomics
- Equilibrium with unemployment
- Incompatibility with standard microeconomics
- It is NOT General Theory, but theory for
economies in depression - The existence of equilibrium in a strict sense
- depends on assumption of rigid nominal wage
4Keynes AD and AS
- AD (for simplicity, still assume pe0, i.e. ir)
- in LVII, slide 39, substitute (5) and (6) into
(1), - Solve (4) for dr
- and substitute into (1) as well we obtain
- AS in the same slide, substitute (3) into (2)
(and dK0) - In AD schedule, increase of P implies decrease of
Y, in AS schedule, increase of P implies increase
of Y
5Keynes equilibrium and policies
- In the more general Keynesian model, we can
construct standard AD and AS schedules - Equilibrium AD x AS intersection
- However, equilibrium determined by position of AD
and does not have to correspond to full
employment one - Keynesian policies shifting AD to the position
where it determines equilibrium at full employment
P
AS
AD2
AD1
Y
Y1
Yf
6Keynes true legacy for policies
- General acceptance of policy recommendations
- Capitalism does not have internal forces to
produce at full employment (potential product)
continuously - The Governments can and should stimulate the
aggregate demand to bring economies closer to
full employment - The General Theory (and its ISLM simplification)
provides the tools fiscal and monetary policies
7First applications
- During WWII, both in UK and in the USA
- White Paper on Employment Policy
- William Beveridge Full Employment in a Free
Society - Oxford Institute of Statistics The Economics of
Full Employment - Policy British budget of 1941, US budgets since
1942
8Keynes vs. real world (1)
- AD and AS above general version of Keynesian
model, AS not very useful for practical for
several reasons - Nominal wage given, inflationary expectation also
constant - In the short-run prices and wages rigid for many
reasons - Informational problem, slow reaction of firms (do
not change prices and wages instantaneously, etc.
see next chapters) - This is true for any point of business cycle, not
only for depression - Consequently, in the (very) short-run, wages and
prices constant aggregate supply horizontal -
SRAS
9Keynes vs. real world (2)
- In the real world the prices adjust and clear
markets, even if in very short run sticky - When capital fixed, then product given by
employment, and when after full adjustment of
prices and wages labor market is in equilibrium
as well, then this (equilibrium) employment
determines full employment and potential product - Neoclassical synthesis in the long-run
aggregate supply vertical (classical) - LRAS
10X.2 The first attempt downward nominal wage
rigidity
- Originally F.Modigliani (1944) downward wage
rigidity - Reasons for rigid wages in general
- Long-term wage contracts, implicit wage
agreements, power of trade unions - Some flexibility upward
- Intuitively if nominal wage rigid, then price
increase lowers real wage ? firms increase
employment ? product increases, i.e. demand
increasing function of price
11Franco Modigliani
- 1918-2003, born in Rome, when young, immigrated
to the USA - MIT
- 1944 elements of neoclassical synthesis (PhD)
- 1953 new theory of consumption function (life
cycle hypothesis) - 1958 contribution to the theory of money,
Modigliani-Miller theorem - 1985 Nobel price in economics
12Model
- Only for situation when product smaller or equal
to potential (full employment) product - Labor market
- Either in equilibrium full employment and
potential product - Or product lower than potential, involuntary
unemployment ? labor supply higher than demand
and level of employment determined by demand
(when , quantity realized on the market
always equal to min (D,S))
13W/P
P
AS
E
E
N
Y
Y
N
14Wage rigidity weakness of the model
- Model explains the relation between the fall or
increase of price and aggregate supply, when
product lower or equal to potential one - Does not consider the situation, when product
temporarily increases above potential level - Real wages move against business cycle
15X.3 Phillips Curve
16Dynamic adjustment
- Nominal wages arent downward rigid forever, but
there is a slow adjustment (beyond the
short-run) ? there is an adjustment of labor
supply over particular moment of time - 1958 A.W.Phillips The Relation between
Unemployment and the Role of Change of Money
Wages. British data. - First investigation before Phillips Irving
Fisher already in 1926 - Inverse relationship between unemployment and
nominal wage change - Phillips statistical fit for 1861-1913
- 1948-1957 data fitted to this curve very well,
too
17Hypothesis
- High unemployment bargaining power of workers
during wage negotiations is weak, firms are able
to hire additional workers without offering much
increase in nominal wage - Low unemployment bargaining power of firms weak,
as to hire more workers they must offer more
substantial nominal wage increase - Wage main component of prices
- Consequently high unemployment implies low
inflation and vice versa
18Interpretation
- Data seemed to suggest that there is a negative
relation between change of nominal wages and
unemployment - Two crucial questions
- Is this a stable, long-term relationship, valid
for other countries as well (see US data on the
next slide, for original Phillips data see
Dornbush, Fischer,Startz in Literature to this
Lecture)? - Many empirical studies followed
- Theoretical explanation of this relationship
- Policy consequences
- As in the short run, change in wages determine
inflation, is there a trade-off between inflation
and unemployment that can be effectively used by
policy makers to simultaneously achieve both low
inflation and low unemployment?
19(No Transcript)
20Phillips curve - concept
- Note here, in LX, we present original approach,
as emerged after Philips article in 1958 - Define unemployment as u(NS-N)/NS
- Remember in K. model, we do not include labor
supply function, but it exists, as NS(W/P) - However, in a particular moment of time, real
wage W/P real wage is known, so value of labor
supply NS is known as well (but in general, - N? NS)
21Phillips curve formalization (1)
- From above
- To simplify, suppose discrete time
-
- and after rearrangement
- Nominal wage in the next period is a function of
current wage and a ratio current employment N and
current labor supply NS
22Phillips curve formalization (2)
- In words wage in next period is equal wage in
the current period, adjusted for the actual level
of employment - At full employment (NNS), next period wage
equals current one - If employment is above full employment, (NgtNS),
wage in next period increases (and vice-versa) - Speed of adjustment parameter e
- Formally at present, W, NS constant ? linear
relation (WN line), with positive slope, between
W1 and N - e large, WN steep. ? small, WN approaches
horizontal
23Wage adjustment
W1
WN2
WN1
WN3
N
NS
N2
N3
WN always passes through (NS,W)
If N?NS, WN shifts in time
24X.4 Dynamic aggregate supply
25From wages to prices
- Short-term labor costs - the only variable costs
- Price determined by current labor costs plus a
mark-up z gt 0 (e.g. profit, embedded in price) - Simplification (for this chapter only) -
production function with fixed coefficients - a ... labor productivity
- labor costs per unit of output (1/a).W
- Price (with incorporation of mark-up)
26Dynamic AS (1)
- Building blocks
- Phillips curve
- Link from wages to prices
- Additional assumption output and unemployment
closely linked (in next Lectures Okuns law) -
- , ?gt0
- Combining three equations above, see next slide
27Dynamic AS (2)
- Remember
- then combining the three equation and
- rearranging
- Simplifying as
28Dynamic AS (2)
- In words price in the next period is equal price
in the current period, adjusted for the
difference between actual output and full
employment one - Difference between actual output and Yf concept
of output gap see future Lectures - AS is very steep for ?gtgt0, very flat for ??0
- Dynamics AS shifts in time (always runs through
point Yf,P) see next slide
29Dynamic aggregate supply
P1
DAS2
DAS
DAS3
Y
Yf
Y2
Y3
AS always passes through (Yf,P)
If Y?Yf, AS shifts in time
30X.5 Long term adjustment
31Adjustment (1)
- Assume starting point Yf at P1 P, different
time periods and increase in nominal money. - Very short run wages (and prices) dont have any
time to adjust ? horizontal AS. An increase in
nominal money leads to decrease in interest rate
i and, because of the larger investment demand,
leads to the increase of overall aggregate demand
? excess demand
32Adjustment (2)
- Short to medium run Excess demand ? firms intend
to increase the production, hiring more people ?
wages (and prices) slowly start to adjust (both
nominal wage and price increase). An initial
shift of AD (in the very short run) is partially
offset, as in medium run, AS is positively sloped - New (static) equilibrium, as intersection of AD
and AS. Not a dynamic one, adjustment not
finished yet - W1 ? W and P1 ? P
- Medium and long run AS continues to shift to the
left till the output doesnt fall back to Yf, but
with higher price P - Both static and dynamic equilibrium restored
33Medium- to long-term adjustment
LRAS
P
C
P
SRAS
B
P1
A
SRAS
P (P-1)
AD
Y
Y1
Y
34Adjustment - summary
- Aggregate demand both in short- and long-run
decreasing function of price - Aggregate supply
- In the long-run vertical at potential product,
long-run aggregate supply (LRAS) - In very short-run (ISLM) horizontal at fixed
price, short-run aggregate supply (SRAS) - In medium term positively sloped AS
- Shifts in AD
- In the long-run, do not change product, but
over-all price level consistent with classical
model - In very short-run, do change the level of product
(and employment), but price is fixed consistent
with original version of Keynesian model
35Short-run shift of AD(external shock that
contracts AD)
P
SRAS
Y
36Long-run shifts of ADexternal shock that
contracts AD
LRAS
P
Y
37From short- to long-run (1)
- Short-run equilibrium
- AD equals AS, adjustment through quantities ? AS
adjusts to AD - Price fixed, equilibrium as state of rest, there
can be excess supply on labor market (involuntary
unemployment) - Actual product can be lower than potential one
- Long-run equilibrium
- AD equals AS
- Simultaneous adjustment of all prices generates
equilibrium on all markets - Actual product equal to potential one
38Long-run equilibrium
P
LRAS
E
SRAS
AD
Y
39From short- to long-run (2)
- Intuitive interpretation
- Fixed price corresponds either to the depression
(Keynes) or to very short-run, when prices (and
wages) are fixed in all economies and at (almost)
all situations (exceptions e.g.
hyperinflations) - Long-run equilibrium prices and wages had to
react to changes in demand/supplies on all
markets (including labor) and their adjustment
cleared all markets simultaneously
40Adjustment in the long-run
P
LRAS
SRAS
A
Y
41X.6 Conclusions
42Neoclassical synthesis - summary
- Neoclassical synthesis in the short and medium
run, a change of policy variables (e.g. G, M,
T(.), etc.) can change (in the Keynesian
tradition) the level of output. However, in the
long run, there is always a built-in mechanism,
which (in the classical tradition) brings the
economy back to the full employment level of
output, albeit with a different price level.
43Phillips curve implication
- There is a trade-off between inflation and
unemployment - Higher unemployment ? lower inflation and vice
versa - Trade off, combined Keynesian demand management
of either fiscal or monetary nature, was
perceived as a basis for Keynesian economic
policy after first period of post-war
reconstruction - This initial belief to potential trade-off
between unemployment and inflation, based on
original Phillips curve, proved to be one of the
biggest mistakes of modern macroeconomics - Later lectures incorporation of inflationary
expectations into Phillips curve
44Literature to Ch. X
- The Phillips curve, derivation of AS and dynamic
adjustment explained here according Dornbusch,
Fischer, Startz, Ch. 6 - Including the simplification when production
function has fixed coefficients and depends on
labor only - Snowdon, B., Vane, H., Modern Macroeconomics,
Edward Elgar Publishing, 2005., pp. 135 144 - More detailed, but simple and comprehensive
explanation - Downward wage rigidity Modigliani, F.,
Liquidity- Preference and the Theory of Interest
and Money, Econometrica XII (1944), pp. 45-88,
reprinted in many Macroeconomic Readings - It is always worth to read this original attempt
to deal with Keynes - General discussion of AD and AS in Keynesian
model Sargent, Macroeconomics, Ch. 2