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The labour market in an equilibrium
business cycle model
Article in Journal of Monetary Economics · January 1983
DOI: 10.1016/0304-3932(83)90017-X · Source: RePEc
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Journal of Monetary Economics 1i (2983) ll?-128. North-Holland
Publishing Company zyxwvutsrqponmlkjihg
THE LABOUR MARKET IN AN EQUILIBRIUM
BUSINESS CYCLE MODEL
George S. ALOGOSKOUFIS* zyxwvutsrqponmlkjihgfedcbaZYXWVUT
London School of
Economics, London W C2A 2AE. UK
This paper extends the basic, multimarket model of Lucas (1972), to explicitly consider the
labour market. It builds on an important distinction between the product wage, entering the
decision function of firms, and the real wage, entering the decision function of workers. Because
of the unobservability of the price level workers make forecasting errors in trying to calculaz
their real wage, despite having rational expectations. This gives rise to a Phillips curve. The
major new result of the paper is the demonstration that wages are less variable than prices.
which offers an equilibrium interpretation of wage stickiness.
1. Introduction
The Friedman-Phelps
tradition of :,$e Phillips curve emphasizes the
informational problems c:sused by the physical separation of individual firms
and markets, and the need for agents to form expectations
about
unobservable economy wide variables. The most popular model in this
tradition today is the model of Lucas (1972, 1973), extended subsequently by
Barro (1976) and others. These models embody the natural rate hypothesis,
which amounts to asserting that agents’ decisions depend only on relative
prices. They also impose the rational expectations hypothesis to arrive at a
set of propositions
about the role of monetary policy that deny any
systematic influence of anticipated money growth on real variables.
This paper presents an extension of the Lucas and Barro models by
introducing an explicit labour market. ILucas and Barro consider an economy
where only one non-durable commodity is traded. In the model of this paper
we consider a similar economy where both labour services and a non-durable
commodity are traded between firms and workers, via a medium of exchange
called money.
The paper builds on an important distinction in the wage variable that
enters the respective decision functions of firms and workers. In particular.
*This paper is adapted from chapter 2 of the author’s Ph.D. thesis. The uuthor gratefull!
acknowledges the comments and suggestions of George Akerlof, Steve Nickel1 and Ch,ris
Pissarides who have acted as thesis supervisors. The comments of the following are ailso
acknowledged: Morley Ashenfclter, Richard Layard, John Nissim, Rafl’u Repullo. Ton! Zabalra.
un anonymous referee and purticipants at various seminurs at LSE and the Centre for Lahour
Economics. Sole :responsibility for remaining shortcomings rests with the author.
firms are interested in their producv wug~, which is the nominal wage they
paqf d~~~t~~ by the price of their output. Workers, however, are interested in
if rt*tiEwuge, which is the nominal wage defiated by the econlomy wide
use of a one period lag in the flow of information across markets, the
ttr price level is not currently observable. Workers have to form
teti;~ about it, which are assumed to be formed rationally. Firms
rve ~JICprice for their otrtput and they do not have an inference
nominal wage in each market is detlermined by the equilibrium of
ad aaid supply for Jabour, and so it depends on tastes, technology, the
ice and the expectations of workers, about t!ze price level.
The analysis confirms the anaJytica1 results derived by the one commodity
f Lucas, and leads to a new result concerning the variability of
Equilibrium nominal wages are shown to display lower
equilibriuni prices. Thus, the alleged ‘stickiness’ of nominal
dative to prices is shown not to be necessarily inconsistent with the
rium approach to macroeconomics. Jt arises naturally in the model
tk inability of workers to observe their current real ::++e, ;as current
ation about the price level is inadequate. It has to be emphasized that
xpioit available information. The model also implies a
live c-ovariance between employment and real wages. This is the familiar
ation of static neoclassical models. Note, however, that, as Sargent
s shown. a dynamic neoclassical model is not inconsistent with the
haviour of real wages over the cycle.
re# of the paper is organized as foJlows: section 2 presents the model.
3 derives rational expectations equilibrium and its properties. The
ult about the Bower variability of wages than prices is also
Section 4 contains conclusions.
P a large number of identical competitive firms distributed over Z
nf markers. Each firm produces a non-storable commodity Y&),
=zf t -.7 . -. 2. In wh%t follows we shall refer to firm z, as a typical firm in
of information within a market is instantaneous, but it lags one
m~rk~ts, This set up is analytically convenient, and yields the
extraction problems emphasized by Lucas (1972, 19731,as
to o&rye economy wide variables currently.
nly factor of production, and the production technology is
The de c isio n func tio ns o f firm s and workers in each market
following: zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
YXZ) =
00 +
are the
O<U,<
1,
(1-a&l,(z), zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(1)
All variables are in logarithms. P,(Z) is average output in market 3, n,(z) is
average employment, w,(z) is the nominal wage, p,(z) the product price, and pp
= Ep, 1Z,(z) is the current expectation of workers about the price level. w,* and
p: are expectations about wages and prices formed at the end of period t .- 1,
where all markets had a common information set. w: -pF is defined as the
normal real wage, and n: as normal employment, which is the level of
employment at the normal real wage. We can think of these normal
variables, as expectations based on the information set available at the end
of period t - 1. Superscript d stands for a demand function, and s for a
supply function.
(1) can be obtained by taking the logarithm of a Cobb-Douglas
production function. (2) is obtained from the first order condition that the
marginal product of labour equals the product wage when firms maximize
profits.’
(3) rests on the intertemporal substitution of leisure hypothesis of Lucas
and Rapping (1969). Labour supply deviates from normal, as the perceived
current real wage deviates from normal.2
It is important to note an important distinction between (2) and (3). Firms
are interested in t.heir procfuct wage, i.e., the wage the pay deflated by the
‘Consider the following production function: Y,(z)=(A;‘(1 - zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPO
CJ~))NJZ)’
-“ :,
A L- 0. zyxwvutsrqponmlkjihgfedcbaZYXW
0 < u2 < I. In
log-linear form it yields (l), where a O=ln 4 -ln( 1-a,). The first order condition for the
maximization of profills is: .~N,(z)-~~= H$z)/P,(z).
In log-linear form it is, In .4 - zyxwvutsrqponmlkjihgfedcbaZ
IJ,~ ,(:) = w,(z)
-p,(z),
which can be rewritten as n:‘(z)= -a; ‘(a, + w,(z)-pJz)). where -11, =In A. Assume there
exists some normal lejvel of employment r$ and a normal real wage ~,:--p:. Then they must
- lJ2
‘(H.,(_‘)- fPI(=i- ~~~+p:I,
satisfy IIF= -a; ‘(a, -+w: -p:). We can then write. &l-n:= zyxwvutsrqponmlkjihgfedcbaZYXWVUTS
whiclh immediately gives (2).
‘The log-linear version of the Lucas-Rapping labour supply function. ignoring assets and the
discount factor, is n;(z);=!+,+ b,(wJz) -pf)b,(wf - p1* ). b,>O, i=O. 1.2. Subtracting b,(n: -p:),
we get: nxz)=b,+(b,-b,)(w:
-pF)+b,(w,(z)-p:-wF+pf).
This is the same as (34 with $*==b,
+(b, - b,)(wf -pr).
Note that since we have another equation for n: (footnote 1). we cau
determine w: --p: by the equality of the right-hand sides. It is given by, H.: --p: =(a,
-a,B,)/(a,(b,
-b;)+
1). The normal real wage in the model is constant. and depends on the
fixed parameters that characterize the technology of firms and the tastes of workers. SC>is
normal employment. ‘f%is is not surprising since the model abstracts from factors accounting for
serial persistence, such as inventory holdings [Blinder and Fischer (1978)], multiperiod lags in
the acquisition of information [Lucas (1975)J convex adjustment costs [Sargent (1’379)], or
shocks with a permanent and a transitory component [Brunner. Cukierman and Meltzer (19X0)].
G.S. Alogwhoufii, Labour m&et
in equilibrium business cycle model
product, whereas workers are interested in their reuE wage, the
t, deflated by the price level. To rationalize this distinction, we
that goods differ in their consumption characteristics, and that
m&e their purchases t’rom a ‘supermarket’ at the end of period,
current market clearing prices. These are determined at the beginning
1 when firms sdi their output to the 6supermarke:f’.3
for commodities in each market is assumed proportional
forthcoming:
14)
is ahe average stock of money forthcoming in market z.
ney stock consists of a deterministic component that can be
using the infomation set available at the end of period t- 1,
te white noise shock and a market specific white noise shock.
ven by
(0, c:), eZY N(O,crz), and m,*= Em,(z)Ii,_1 = Em,ll, _ I . m, is the
y wide average money stock4* 5
mode4 is now completely descsibed. (4) and (1) are the demand and
for output, and (2) and (3) is the demand and supply for labour
e can now proceed to impose rational expectations equilibrium.
assumption about the flow GCinformation across markets, workers
observe the price level when they make their labour supply decision.
they have a genuine inference problem. On the other hand, firms
variables enting their decision functions.
us first consider the determination of expected prices under the
ioa that normal employment is n,* and the money supply is aa m,‘.
marginai productivity of iabour, firms make positive
are distributed to workers who own identical portfolios
economy. No Scapitalmarket operates. A less restricted set of
talmdet
can be found in Barro (1980).
created by the lack of double: coincidence of wants
Of course its role could be played by a ‘clearing zyxwvutsrqpo
m o de l is by no means a full description of a
essential features of such an economy.
to be any rule. For example, Barro 11976) uses m,_ , as the
pply. As all results can be proven for a general specification
G.S. Alogoskoujis. Lahour market in equilibrium business cy cle model
By the commodity
market equilibrium
I21
condition,
* zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
+(l ---a&z,*.
Pi = -ua,+m:
(6)
It is easy to see from (6), that the elasticity of expected prices with respect
ta expected money is unity.
We can next consider rational expectations equilibrium. The details of
imposing the equilibrium conditions in the commodity and labour markets
are in the appendix. Assuming’that workers derive an optimal forecast of the
currently unobservable price level, by using all information up to the end of
period t- 1, plus an observation of their current market specific price, we get
the following reduced form price equation:”
Pi@)= P: +
8=
l+n,b,
’
(4 + G),
1 +b,[l -d(l -at)]
(7)
a,Z/(a,2
i- a,2).
8 is the proportion of demand variance in an individual market which is
attributable to aggregate demand variance. It enters (7) through the optimal
signal extraction of workers.
The price equation can be decomposed into a part due to aggregate
factors, and another due to market specific factors. They are respectively
defined as,
Pt=Pt*fYut,
rz = ye,,
(8)
where
l+a2b1
Y=l+b,[l-B(l-a,)]
(9)
<l
’
, We can therefore rewrite the price equation as in Lucas (1973),
(10)
where
“The details of the derivatifon of this equation are in the appendix.
!22
G.S. Alogoskot&s,
Labour market in equilibriuwJ businexs cycle model
It is easy to see that
PF- Pf = Jet - Pa 1Md = 8(Pl(z)
- P3.
(12)
Before going on to examine the equilibrium wage distribution, we derive
some comparative statics properties of the price level, using (8).
First, the elasticity of the price level with respect to anticipated money is
unity,
++ldM
I “,,@ = @p,@pf)@p,*
/iii%,*)
=
1.
(13)
Second, the elasticity of the price level with respect to unanticipated
is fess than one, which immediately indicates that unanticipated
affects output and employment,
money
money
Third, the partial derivative of y with respect to the share of demand
var&& that is attributed to aggregate factors, is positive, zyxwvutsrqponmlkjihgfedcbaZYXWVU
d2P,
h,ze
b*(l -a2KI+a,h)
m'=
,
(1 +b,[l-e(l
-a2)])2
>()
-
(15)
The higher the fraction of demand variations that is attributed to
regate factors, the higher the influence of unanticipated monetary growth
on the price level.
All these results are in accord with the one commodity business cycle
models of Lucas (1973) and Barre (1976).
The equilibrium condition in labour markets gives the following wage
equation?
Corisider first the divergence crf the firms’ product zyxwvutsrqponmlkjihgfedcbaZYXWVUT
wa g e fro m no rm a l. It is
w&l to ,
(17)
from eq. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(A.12) in the appendix.
by the use of (16). (17) implies that in equilibrium, product wages are lower
than normal in markets where p,(z)-pjf: >O, and higher than normal in
markets where pXz)-p,* ~0. Labour demand rires or falls correspondingly.
These movements in product wages are accompanied
by opposite
movements in perceived real wages. By ( 12) and (16) the divergence of
perceived real wages from normal is equal to
:,“h(PM - P3. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPON
(18)
Mz)--w,*)--_(P:--P,*)=
*
2
I
Since 1 - 0>0, perceived real, wages move in an opposite direction from
product wages. Therefore, as equilibrium product wages move in an opposite
direction from perceived real wages, equilibrium labour demand and supply
move together. Following an unexpected increase in demand, nominal wage
changes are such, that the product wage falls, and perceived real wages rise.
For unexpected decreases in nominal demand, the opposite apply.
To derive the distribution of the aggregate wage level, we average (16) over
markets. We get
w,= NJ,*+-
I+ a,!@
* +*
b (Pt-P3
3 1
(19)
From (19), variations in the aggregate wage level take place according to a
normal distribution, with mean w,* and variance,
The variance of wages is smaller than the variance of prices, because the
term in brackets is less than unity. (20) offers an equilibrium interpretation of
the relative stickiness of wages vis-a-vis prices and is the major new result of
this paper.8
The intuitive explanation for this result is the following: Workers do not
observe the price level, but only their market specific prices. When
unanticipated inflation occurs, prices in all markets are higher than the case
would have been otherwise. Workers in each and every market, optimally
attribute some of the: ‘rise they observe, to market specific factors. As a result.
they demand less than a proportional rise in their nominal wages. Firms arc
prepared, because of favourabfe demand, to offer them a higher increase than
that which would induce them to offer their normal labour supply.
“The variance is not of course in general an appropriate measure of variability. In our case
where distributions are normal it is, however, a suitable measure. See Rothschild and Stiglitz
(1970).
C&S. Abgoskoujis, Labour marker in equilibrium hslness cycle model
I24 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
uently, they work more than normal. In a symmetrical way, with
ted deflation, prices in all markets are lower than the case would
otherwise. Workers are not willing to accept a proportional wage
in each market, they attribute some of the fall they observe, to market
faors. Therefore, they again demand less than a proportional fall in
inal zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
wages, Firms are again prepared, becsuse
of unfavourable
d~~nd,
ta offer them a higher decrease than that which would induce them
to oXJer their normal labour su,pply. Consequently they work less than
~~~al~ Et is the same intuition that is implicit in Friedman (1968) and Lucas
61973).it can be algebraically demonstrated by considering,
fr
fl9). (21) is positive because both terms in the right-hand side are
-five; it is less than unity because both terms are less than unity; and it is
aller than t~p,/ih, because the first term in the product of the right-hand
e is less than unity. The fact that wages respond less than prices to
tc shocks, induces fluctuations in real wages. Had there been no
sion between aggregate and relative demand shocks, i.e., O= 1, the real
would be constant.
Tu derive a Phillips curve, we can substitute (17) in the demand for labour
1. Koie that (17) is the equilibrium wage equation, and we could as well
titute in the supply of labour equation.
nJz)=n,*+-
1-s
az zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(P,(Z5- P3,
42q
where B=( 1 +rz,b,B)/( I+ azbl)= b,/dP. Clearly, (i-6)/a,
=(bp- 6,,)/u2bp
> 0.
Averaging over markets, we get an aggregate employment function,
(23)
123) is analogous to the aggregate supply function of Lucas (1973).
However, it is derived, as implicit in the analysis of Lucas (1973)
or Barro
~~76~from a formal explicit modelof the labour market9
784)has demonstrated that the auction market outcome is only efficient if firms
ve the dirlnte degree of relative risk aversiort. The auction market outcome is
t Enthis model. as we hue not assumed that the tastes of firms and workers towards
To derive the covatiance of employment and the real wage. we subtract +
and p, -p: from both sides of 619). This gives us
w,- - p,- w,*+p:=
-
a2h,(! - 8) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK
, +c r h- - (Pc - P:).
2
(24)
t
Using (23) and (24),
(2.5)
Thus, the present model imphes a negative association
between
employment and real wages. However, it should be born in mind that
normal wages and employment have been assumed constant and we have
not been concerned with factors accounting for serial persistence. As Sargent
(1978) has shown, a dynamic neoclassical model is not inconsistent with the
actual behaviour of real wages over the cycle.
4. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
C o nc lusio ns
This paper extends the basic multimarket, stochastic equilibrium model of
Lucas (1973) to explicitly incorporate a labour market. The model is built
around the important distinction between the product wage, entering the
decision function of firms, and the real wage entering the decision function of
workers. The real wage is currently unobservable because the price level is
only known with ? one period lag.”
Workers are assumed to form rational expectations about the price level.
However, they cannot distinguish perfectly between relative and absolute
price shifts as they do not have enough information. The end result is that
wages fluctuate less than prices. This endogenous sluggishness of nominal
wages is the major new result of this paper. The sluggishness of wages is not
imposed as in Phelps (1969). The labour market is an auction market. It does
not rest on expectational non-neutralities,
either. It is only due to the
unobservability of the price level. That is what allow:; for purely monetar)
shocks to have real effects, such as fluctuations in real wages. employment
and output. Thl.: implied covariance between real wages and employment is
the familiar negative one of static neoclassical models.
“It has been argued that, whereas workers in modern economies do not even know the price
of their product, they know the prices or a host of other prodUs which they encounter in their
daily purchases. However, as long as workers do not fully observe the price level. the qualitative
implications of this paper are not modified by this objection. If more prices are being observed.
workers get a better estimate of the price level and the employmsnt-unanticipated
intlation
tradeoff gets steeper. ‘This has been shown by Cukierman {I9791 for the one commodity model.
G.S. Alogoskoujis, L&our market in equilibrium businw
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIH
cycle model
526
iw:
A
De&a-
of rational expectations equilibrium
commodity market equilibrium condition gives
p&S= -~ao+m~+u,+e,-(l
-a&(z).
(A.1)
Subtracting the relevant ex ante condition, eq. V99
pfjz)= pf + u, + 6zz- (1 - a&(z) - n,*).
(A.21
&2)
states that the deviation of market prices from what had been
. is equal to the money supply shocks, dampened &y the deviations
ayment from normal. Employment, however, is an endogenous
rhMe simultaneously determined with prices.
The h&our market equilibrium condition gives
(A.3)
ate that, if pf = PAZ),then, w,(z)-p,(z) = W:-p,*, and the product and real
are equal at their constant normal level.
Substltuiing the equilibrium wage equation in the demand for labour, eq.
CL gives
(A.41
Substitalting for n,(z), in tA.2) from (A.4), and solving for p,(z),
(A.9
To arrive at a price equati’on in terms of predetermined and exogeno?Js
aCab& we have to substitute for p: in terms of such variables. It is here
c the rational exmtations
hypothesis is imposed.
t method to solve for rational expectations equilibrium is the
of undetermined coeffncients.
we postulate an equation for &z), depending only on predetermined
ous variables, which in this model are p,*, u,, e,. Such an equation
P&HhPi*+wl+q3ez,
ng the undetermined coefficients.
(A.61
G.S. Alogosko~fis, Labour market in eyuilihriunr zyxwvutsrqponmlkjihgfedcbaZYXWVUTSR
hrlsirwss c pde rnm d d
127
Averaging (A.6) over markets we get an equation for the price level,
(A.71
Since we have assumed that e, has a zero mean, upon averaging over a
large number of markets, this term disappears.
Imposing. the assumption that individuals have rational expectations
amounts to requiring that they know the zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHG
q’s.
The expected price level given
market specific information is
P~=EP,
Ih@)=q,p:+q,E~,I
(A.8
l,(z).
The information
set is assumed to contain, in addition to r’,_ , , an
observation of the market clearing price in the specific market. Since
individuals know p: from the end of the previous period, the additional
information contributed by zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
p&j is an observation of the sum q+,+
q3eE.
Since both random variables are normal, the conditional expectation of U, is
given by the regressiou of U, on the aforementioner? sum. This is a simple
application of the signal extraction problem [Sargent ( 1979)],
The 8 coeficien- measures the fraction of total price variance produced by
aggregate demand variance, The remaining fraction, 1-0,
measures the
fraction attributable to market specific variance.
Substituting (A.9) in (4.8) gives
(A.10)
Su‘bstituting (A.lO) in (A.5) gives
1 +a,b,
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(1 -adb, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONML
P,(z)=--
1 +b
(Pt*+“,+e,)
+
CqIpI*+~(q,u,$-q,e,)l. (A.11)
z +b zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK
1
1
We now have two equations for p,(z), (A.6) anti (A.1 I), both in terms of
exogenous variables. By comparing coefficients,
41 =
1,
1 +a2b,
-‘* = 1 cb,[lH(1--rr,)]
43=Yz.
l
G.S. Alogoskoujis. Labour zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
market in equilibrium business cycle model
f28
By substituting for tF’ceq’s in (A.@,eq. (7) is obtained.
To obtain the wage equation, we first note that the labour market
aquilibrium condition, (AL+),can be written as
(A.12)
By substituting for p;-- ,pf from
i It?),
eq. (16) is obtained.
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xpectations and the role of monetary policy, Journal of Monetary
market in an equilibrium business cycle model. Econometrica 48,
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Nman,M., 1968, The role of monetary policy, American Economic Review 58. l-17.
r, J.R.. 1967, Critiodl essays in monetary theory (Oxford University Press, London).
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~~~~~~~
Scl.E..Jr., 1973, Some international
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tradeoffs, American
Jr.. 1975, An equilibrium mode1 of the business cycle, Journal of Political Economy
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tical tionomy 77.721-754.
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and inflation, Journal of
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E% et aL 1970, Microeconomic foundations of employment and inflation theory
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Stiglitz. 1970, Increasing risk: I. A definition, Journal of Economic
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t. TJ, I97Y. Macroeconomic theory (Academic Press, London).