Transcript Document

Chapter16
Money and Business Cycles II:
Sticky Prices and Nominal Wage Rates
Macroeconomics
Chapter 16
1
The New Keynesian Model


From equilibrium to disequilibrium
model
Sticky price
Macroeconomics
Chapter 16
2
The New Keynesian Model

2 Extensions:

Imperfect competition:
the typical producer actively sets its price.

Menu cost

Journal price
Macroeconomics
Chapter 16
3
The New Keynesian Model

Price Setting Under Imperfect
Competition


Let P( j ) be the price charged for a good
by firm j.
the quantity demanded of firm j ’s goods
is q( j )
Macroeconomics
Chapter 16
4
The New Keynesian Model

Price Setting Under Imperfect
Competition

Typically, q(j) depends on


relative price P( j )/P
the income of consumers
Macroeconomics
Chapter 16
5
Extra: Price Setting Under Imperfect
Competition

Pure Monopoly



A single seller, who chooses price and
quantity to maximize profits.
Entry into the market is completely
blocked by technological or legal
barriers.
The monopolist’s profit-maximization
problem:
max  q   pq q  cq 
q
Macroeconomics
Chapter 16
6
Extra: Price Setting Under Imperfect
Competition

FOC: MR(q)  p' qq  pq  c' q  MC (q)
 p' q 

 pq 
q  1  c' q 
 pq 



1
  c' q 
 pq 1 




q



 q   1 is the elasticity of market
demand at output .
Macroeconomics
Chapter 16
7
Extra: Price Setting Under Imperfect
Competition
Cournot Oligopoly:
•
J identical firms produce a homogeneous good.
• The choice variable is the quantity.
All firms choose simultaneously.
•
•
Their cost function is same: C q j   cq j
The inverse market demand is :
p  a  b q j
a  0, b  0, a  c
j
Macroeconomics
Chapter 16
8
Extra: Price Setting Under Imperfect
Competition

The profit function of firm j is:

k j
 q    a  b q q  cq j
k


d j q 
k
j
FOC:
j
dq
j
 a  c  b q  2bq  0 j
k j
ac 1
q 
  qk
2b
2 k j
j
Macroeconomics
Chapter 16
j
9
Extra: Price Setting Under Imperfect
Competition
J
ac 1
 q  J
  J  1 q k
2b 2
k 1
k 1
J
k
J ac
 q 
J 1 b
k 1
J
k
qj 
ac
j
bJ  1
J a  c 
p  a
J 1

a  c
pc 
J 1
J 
Macroeconomics
J 1
Chapter 16
10
Extra: Price Setting Under Imperfect
Competition



Under imperfect competition, each
firm can set P( j ) above its nominal
marginal cost.
The ratio of P( j ) to the nominal
marginal cost is called the markup
ratio
firm j ‘s markup ratio
= P( j)/MC( j)
Macroeconomics
Chapter 16
11
Extra: Price Setting Under Imperfect
Competition


P( j) = (markup ratio) · MC( j)
The production function for firm j looks like
the function we have used before:
Y( j) = F[κ( j) · K( j) , L( j) ]

MPL( j) = ∆Y( j)/ ∆L( j)
Macroeconomics
Chapter 16
12
Extra: Price Setting Under Imperfect
Competition

MC(j)
= w/ MPL( j)

P( j) = (markup ratio) · [w/ MPL( j)]
Macroeconomics
Chapter 16
13
The New Keynesian Model

Short-Run Responses to a Monetary Shock

Imagine M doubles.
 P( j ) doubles when M doubles.
 The average price, P, doubles
 The nominal wage rate, w, also doubles



The economy-wide real wage rate, w/P,
Relative price, P( j )/P.
These changes leave unchanged the real
variables in the economy.
Macroeconomics
Chapter 16
14
The New Keynesian Model

Short-Run Responses to a Monetary Shock
with Sticky Prices




The average price, P, would then also be fixed.
If P is constant and M doubles, each household
would have twice as much real money, M/P, as
before.
However, nothing has changed to motivate
households to hold more money in real terms. Each
household would therefore try to spend its excess
money, partly by buying the goods produced by
the various firms.
Each firm j would then experience an increase in
the quantity demanded of its goods, Yd( j ).
Macroeconomics
Chapter 16
15
The New Keynesian Model



To raise its production, Y( j ), firm j has to
increase its quantity of labor input, L( j ).
Therefore, the quantity of labor demanded,
Ld(j), rises by the amount:
∆Ld( j) = ∆Y(j)/MPL(j)
With a fixed price P( j ), an increase in the
nominal quantity of money, M, leads to an
expansion of labor demand by each firm j .
Macroeconomics
Chapter 16
16
The New Keynesian Model
Macroeconomics
Chapter 16
17
The New Keynesian Model



An increase in the nominal quantity of money from M
to M’ raises the market-clearing labor input from L∗ to
(L∗)’ on the horizontal axis.
With the increase in labor input, each firm produces
more goods. Thus, real GDP increases.
We therefore have that a monetary expansion is nonneutral. An increase in the nominal quantity of money
raises real GDP. Moreover, labor input, L, moves in a
procyclical manner—it rises along with Y.
Macroeconomics
Chapter 16
18
The New Keynesian Model

New Keynesian Predictions


The predictions from the new Keynesian
model are similar to those from the
price-misperceptions model.
That model also gave the result that a
monetary expansion raised real GDP, Y,
and labor input, L.
Macroeconomics
Chapter 16
19
The New Keynesian Model

Difference between the two models: w/P
 the price-misperceptions model, an
expansion of L had to be accompanied by a
fall in w/P in order to induce employers to
use more labor input.


that model predicted—counterfactually—that
w/P would be countercyclical.
that a monetary expansion increases the
market-clearing real wage rate from (w/P)∗
to [(w/P)∗]’ on the vertical axis. Therefore,
the model generates a procyclical pattern
for w/P.
Macroeconomics
Chapter 16
20
The New Keynesian Model

New Keynesian Predictions


Keynesian model predicts,
counterfactually, that Y/L would be
countercyclical.
Keynesian economists have used the
idea of labor hoarding to improve the
model’s predictions about labor
productivity.
Macroeconomics
Chapter 16
21
The New Keynesian Model

Price Adjustment in the Long Run



In the long run, the prices adjust, and
tend to undo the real effects from a
change in M.
P(j) = (markup ratio) · [ w/ MPL( j) ]
The real effect of a monetary shock in
the new Keynesian model is a short-run
result that applies only as long as prices
fail to adjust to their equilibrium levels.
Macroeconomics
Chapter 16
22
The New Keynesian Model

Comparing Predictions for Economic
Fluctuations


The new Keynesian model correctly predicts a
procyclical pattern for the real wage rate, w/P,
and a countercyclical pattern for the price level,
P.
The new Keynesian model errs by predicting a
countercyclical pattern for Y/L, although the
idea of labor hoarding might fix this problem.
Macroeconomics
Chapter 16
23
The New Keynesian Model
Macroeconomics
Chapter 16
24
The New Keynesian Model
Back to assumption: sticky prices


Data do reveal stickiness of some
prices.
However, a tentative conclusion from
empirical research with these new data
is that price stickiness is insufficient to
explain a major part of economic
fluctuations.
Macroeconomics
Chapter 16
25
The New Keynesian Model

Shocks to Aggregate Demand

Each firm j experienced an increase in
the demand for its goods, Yd(j), while
its price, P(j), was held fixed. The same
results apply if Yd(j) rises for each firm
j for reasons having nothing to do with
money. The essential ingredient is an
increase in the aggregate demand for
goods.
Macroeconomics
Chapter 16
26
The New Keynesian Model

Shocks to Aggregate Demand


One way for aggregate demand to rise
is for households to shift exogenously
away from current saving and toward
current consumption, C.
Another possibility is that the
government could boost the aggregate
demand for goods by increasing its real
purchases, G.
Macroeconomics
Chapter 16
27
The New Keynesian Model

Shocks to Aggregate Demand


An increase in the aggregate demand
for goods may end up increasing real
GDP, Y, by even more than the initial
expansion of demand.
That is, there may be a multiplier in
the model—the rise in Y may be a
multiple greater than one of the rise in
demand.
Macroeconomics
Chapter 16
28
Money and Nominal Interest Rates


In practice, central banks tend to express
monetary policy as targets for short-term
nominal interest rates, rather than
monetary aggregates.
In the US, the Fed focuses on the
Federal Funds rate—the overnight
nominal interest rate in the Federal
Funds market.
Macroeconomics
Chapter 16
29
Money and Nominal Interest Rates


The Federal Reserve’s Federal Open
Market Committee (FOMC) meets eight or
more times a year. At each meeting, the
FOMC adopts a target for the Federal
Funds rate.
The central idea is that, in the short run
with sticky prices, open-market
operations affect nominal interest rates—
the Federal Funds rate in the United
States and the nominal interest rate, i, in
our model.
Macroeconomics
Chapter 16
30
Money and Nominal Interest Rates




M= P · L( Y, i)
In the new Keynesian model, P is fixed in
the short run.
Thus, if M increases, equilibrium requires
some combination of higher Y or lower i
to raise the nominal quantity of money
demanded by the same amount.
For a given Y, a higher M has to match up
with a lower i
Macroeconomics
Chapter 16
31
Money and Nominal Interest Rates


In our previous analysis, we thought of an
expansionary monetary shock as an
increase in the nominal quantity of money,
M.
Now we can think of an expansionary
monetary action as a decrease in the
nominal interest rate, i .
Macroeconomics
Chapter 16
32
Money and Nominal Interest Rates


Central banks have rejected proposals,
originally put forward by Milton Friedman,
to have a constant-growth-rate rule for
a designated monetary aggregate.
An important point is that the Fed does
not have to know the exact specification
for L(Y, i). The Fed just keeps raising M
until it sees the nominal interest rate that
it wants
Macroeconomics
Chapter 16
33
Money and Nominal Interest Rates
Macroeconomics
Chapter 16
34
Monetary Policy

The goal of monetary policy


Growth rate of GDP and unemployment
rate?
--Greenspan
Inflation rate
--Bernanke
Macroeconomics
Chapter 16
35
The Keynesian Model—Sticky Nominal
Wage Rates

John Maynard Keynes:
The general theory of Employment, interest and money
1936
 Did not explain the origins of the Great Depression
 Active fiscal policy
 Keynesian economics: government intervention at the
macroeconomic level can help to improve the
functioning of poorly performing market economies.

Milton Friedman:
 The origin of the Great Depression is on
government failure.
Macroeconomics
Chapter 16
36
The Keynesian Model—Sticky Nominal
Wage Rates


Sticky nominal wage rates — that is,
a failure of nominal wage rates to react
rapidly to changed circumstances.
Perfect competition. — In this setting,
the single nominal price, P, applies to all
goods.
Macroeconomics
Chapter 16
37
The Keynesian Model—Sticky Nominal
Wage Rates


Keynes focused on a case in which
w was higher than its marketclearing level.
This assumption will imply that the
real wage rate, w/P, will be above
its market-clearing value.
Macroeconomics
Chapter 16
38
The Keynesian Model—Sticky Nominal
Wage Rates
Macroeconomics
Chapter 16
39
The Keynesian Model—Sticky Nominal
Wage Rates

The excess of the quantity of labor
supplied (at the given real wage
rate, [w/P]) over L’ is called
involuntary unemployment.
Macroeconomics
Chapter 16
40
The Keynesian Model—Sticky Nominal
Wage Rates


Suppose, now, that a monetary expansion
raises the price level, P. If the nominal
wage rate, w, does not change, the rise in
P lowers the real wage rate, w/P.
This fall in w/P raises the quantity of labor
demanded, Ld, and, thereby, increases
labor input on the horizontal axis from L’ to
L’’.
Macroeconomics
Chapter 16
41
The Keynesian Model—Sticky Nominal
Wage Rates
Macroeconomics
Chapter 16
42
The Keynesian Model—Sticky Nominal
Wage Rates

With sticky nominal wage rates, a
monetary expansion raises labor
input, L. The increase in L leads
through the production function to
an expansion of real GDP, Y.
Macroeconomics
Chapter 16
43
The Keynesian Model—Sticky Nominal
Wage Rates



The Keynesian model is similar to the new
Keynesian model in predicting that M and L
would be procyclical.
However, unlike the new Keynesian model,
the Keynesian model predicts that w/P
would be countercyclical.
We have stressed that w/P typically moves
in a procyclical manner. Therefore, the
Keynesian model has difficulty explaining
the observed cyclical behavior of w/P.
Macroeconomics
Chapter 16
44
Long-Term Contracts and Sticky
Nominal Wage Rates


Existence of long-term contracts: avoiding
hold-up problems
Setting the nominal wage rate w in advance
by rational expectation:


no systematical errors
hard to support Keynesian assumption that w is
greater than w∗
Macroeconomics
Chapter 16
45
Long-Term Contracts and Sticky
Nominal Wage Rates


Another argument: aggregate shocks can
create differences between w and w∗.
However, logic problem:
w/p > w∗/p  L=Ld<Ls happens in an impersonal
market, not in a case of long-term contract

Long-term contract doesn’t necessarily
cause errors in determination of L and Y.
Macroeconomics
Chapter 16
46
Long-Term Contracts and Sticky
Nominal Wage Rates

An important lesson from the
contracting approach:

Stickiness of the nominal wage rate, w,
need not lead to the unemployment and
underproduction that appears in the
Keynesian model.
Macroeconomics
Chapter 16
47
Long-Term Contracts and Sticky
Nominal Wage Rates

Important empirical works:


Ahmed(1987): index contracts
Olivei et al. (2007): shocks in different seasons
have different effect.
Macroeconomics
Chapter 16
48
Extra: IS-LM model
Y CI
 Y  C (Y )  I (r )
r
S(y)
 S (Y )  I (r )
I(r)
I,S
Macroeconomics
Chapter 16
49
Extra: IS-LM model
S (Y )  I (r )
r
Y
Macroeconomics
Chapter 16
50
Extra: IS-LM model
M  P  L(Y , r )
i=r
Assume now that
P is fixed
M/P
Macroeconomics
Chapter 16
51
Extra: IS-LM model
M  P  L(Y , r )
r
Monetary policy:
M increases
Y
Macroeconomics
Chapter 16
52
Extra: IS-LM model
Equilibrium:
r
S(Y )  I (r )
M / P  L(Y , r )
Monetary policy:
M increases
Y
Macroeconomics
Chapter 16
53
Extra: AD-AS model
Aggregate Demand :
r
M fixed and P decreases
LM curve moves down
R decreases and
Y increases
Y
Macroeconomics
Chapter 16
54
Extra: AD-AS model
Aggregate Demand:
P
P decreases and
Y increases
Y
Macroeconomics
Chapter 16
55
Extra: AD-AS model
Aggregate Supply :
P
Long run:
Y is fixed
Short run:
P is fixed
Y
Macroeconomics
Chapter 16
56
Extra: AD-AS model
Aggregate Supply :
r
IS
Long run:
LM
Y is fixed
Short run:
P is fixed
Y
Macroeconomics
Chapter 16
57
Extra: AD-AS model
Aggregate Supply :
P
AD
LRAS
Long run:
Y is fixed
Short run:
SRAS
P is fixed
Y
Macroeconomics
Chapter 16
58