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I. TRADE MODEL WITH INCREASING RETURNS TO SCALE, ZERO PROFIT AND THE COBB-DOUGLAS UTILITY FUNCTION
Recent development of trade theory in the area of market structure,
returns to scale,etc have enhanced our understanding of the cause of trade. While
writing the theory of factor proportion early in 1933. Ohlin pointed out that
economies of scale in production provide an incentive for international
specialization and trade, even in the absence of cross-country differences in factor
endowment.
Using the increasing returns to scale production functions of both X and
Y industry which we've got earlier in the introduction part, we will try to show
that both factor endowment and returns to scale play an important role in
deciding the trade pattern under certain conditions.
Unlike the case of perfectly competitive and constant returns to scale
where there is no clear focus on firms in the market, we will discuss some issues
of individual firrns in the oligopolistic structure of increasing returns to scale. In
the following, we assume general production function with increasing returns to
scale, zero profit in the long run and Cobb-Douglas utility function for knowing
the trade pattern in an autarkic general equilibrium model.
Production function of a representative firm in each of the two industries
producing goods X and Y are :
28
(1)
Where X and Y are firm outputs, Lx and LY are labour units employed, kx and ky
are capital labour ratios, rx and ry returns~to-scale parameters in the two
industries respectively. For the assumption of increasing returns to scale, ri(i =x,y)
is strictly larger than one, but less than 2 for profit maximization. This point will
be elaborated in the next part and also in the appendix. (0 < ri < 1) represents
decreasing returns to scale.
Let rr x and rr Y be the profits of representiye firms, defined as
1tx = Px(X,Y)X - WLx - rKx
(2)
Where Kx and~ are capital stocks, Px,Py prices and W ,r nominal wage rate and
- -rental price of capital, X = ~X and Y = I; Y are total outputs in the two
industries. Factor prices are assumed to be the same in the two industries as
there is no imperfection in the factor markets. The product markets are assumed
f0 be oligopolistic. The firms in each industry produce a homogeneous product
nnd follow Cournot·type conjectural variation in their profit maximizing
- -behaviour. In other words, dX/ dX = d Y I d Y = 1 . At the firm level decision-
- -making X and Y are assumed t() have no effect on PY and Px respectively.
29
Maximizing *the first profit function in (2) with respect to Lx and Kx and the
second with respect to LY and KY, we get
a1tx = [P~(X)X + 'px(X)]XL = W aLx
anx = [P~{X)X + Px(X)]XK = r aKx
a1ty = (P~(Y)Y + Py(Y)]YL = W aLy
a1ty = [P~(Y)Y + Py(Y)]Y K = r aKy
(3)
Wher~ Xi and Yi(i=L,K) are the marginal products oflabour and capital in the
two industries, which may be written as:
rx-1 1\ XL = Lx (rxf - kxf,
Y - Lry-lh' K - y
(4)
Expressing the marginal revenue terms m equation (3) m terms of pnce
elasticities, we get
*
I - 1 Px (X) X+ Px = Px(l---)
exnx (5)
Further details are given in the appendix where second order conditions are discussed
30
Where nx = X/X and ny = Y /Y are the numbers of identical firms in the two
- P aY P industries respectively and e = - ax . ~ and e = -- .! are the market
X apx X y apy y
de mend elasticities. The number of firms is determined in a situation where each
firm earns zero profit in the long run. Using (2),(3),(5) and the Euler's law we
get
,, = P,(XJx{l-r,(l- e,lnJ} ~ 0
", = Py (Y) v{l-r,( 1 - e,ln,)} = 0
This gives us
i = X,Y
(6)
6(a)
We assume that the social utility functiton is Cobb-Douglas and therefore the
demand elasticities, € x and EY are unity. Thus, the number of firms is uniquely
determined by the returns-to- scale parameters:
ri n. = -- i = X, Y 6(b)
1 r.- 1 1
In this model ri is strictly greater than one. The number of firms is inversely
related to ri. For instance, if ri is close to unity, say 100/99, the number of firms
will be 100. ni is infinitively large in the constant return-to-scale case. We also
assume ri to be less than or equal to 2. For the sake of simplicity we do not
impose any integer constraint on ni. Since ri is a parameter of the model, its
values can he S0 chosen that ni ·iS an integer.
31
As the factor marginal productivity should be equal to the factor price for
firm's profit maximization, we use (3), (5) and (6) to get
p Py 2X = -YL =W r L ry
X
(7)
p Py 2X = -YK = r r k ry
X
We get the factor price ratio ( w) in each X, Y industry
W r/ -f'kx r h- h'k· (&) = - = = y y
r f' h1 (8)
Now, we turn to the demand side for knowing the price ratio. Maximizing the
Cobb-Douglas Utility Function
U = D" DP X y
We get
etDa-1D 11 -J..P = 0 X Y X
AD"DP-l_).p = 0 tJ X y y
D P +D P =I X X y y
Where ). is the Lagrange multipli_er.
I = National Income
Di =Demand, i = X,Y
In a closed economy, Dx = X = nxX ; Dy = Y = ny Y
From the above equations, we get
~ Dy = px p Dx py
32
(9)
9(a)
P = Price ratio
p X nxX nxL:1 f(~) (10) = --=-=Y- = y ex y nYY nYL;rh(~)
Where, ~ = y a
We get the following from the equility of marginal value productivity of capital
in (7) after using the expressions of marginal product of capital in( 4) and price
ratio in (10)
f l n h 1L X X
= y rxf nyryhLY
For rewriting Lx/LY' we use full employment condition.
( L +L = L
X y
- -LX~ + Ly~ = K
-L
X
Px = -=- ' L
-L
P = ...2. y -
L
( 11)
11(a)
Now, we have seven equations, 6-(a),(8),(10),(11) and 11-(a) and seven
unknowns kx ky ,px, pY' P, nx and ny for solving our closed equilibrium.When we
solve the above, equation ll(a),, we get
Using pj Py• we rewrite the above equation (11)
f I = y hI p x = y hI (ky-k)
ri ryh Py r~ (k-kx)
33
(12)
we get, ll(b)
Therefore, we get the two reducep form equations (8) and ll(b) in terms of the
factor endowment ratio, k to solve for kx and ky
We rewrite the equal factor price equation (8) as:
r ,.f - k,.f 1
f' Therefore,
f r --k = w
X f'. X
or
w + k ri
--X f'
or 1 f' --- --
w+k X ri
h -k = w r-y h' y
w +k = r)l y h'
1 h' --
w+~ r)l
8(a)
(13)
\Ve rewrite the equal marginal capital productivity equation ll(b) with the help
of(13).
f1(k- kx) = Y h 1~ -k) = (k-k.~) = Y (~ -k)
ri r)l (w+kx) (w+~) ll(c)
Let's find the relationship between labor ratio in X industry (Px) and that of Y
industry (Py) using (13).
=
34
k-k X 1 k-k w+k
X y = = y • ky-kx • W + ~
1 (A) +ky = -p -
y y (&)+~
We get
w+k YPx = P ____r
Y w+k X
•
by (12)
(14)
We define the elasticity of factor substitution ( ai) with respect to factor price
ratio (w).
ak, w w a.=-.-=---1 aw ki kiw'(ki)
= x,y .(15)
Let's differentiate the changed equal factor price ratio equations 8(a) and equal
marginal capital productivity condition ll(c) using the above equations.
8(a)
By differentiation,
Using the definition of elasticities of factor substitution (15),we get
We change the above equation into variational form with an asterisk denoting
relative rate of change
35
(16)
Differentiate totally 11(c)
(k-k) k -k __ x_ = Y ___..!....Y_
U> + kx ( U> + ~) ll(c)
Then,
(w +kx)(dk-dkx) -(k-kx) {w 1(kx)+ l}dkx = y (w +ky)(dky -dk)-~ -k) {w'(ky) + l}ill).
(w+~)2 (w+~i
we arrange,
by (16)
= [ ~(w +kx)+~(k-~){1 +w 1(~)}]~ + [~(w +~)-~(~ -k){1 +w'(~)}ly oYI<
(w+~i (w+~)2 ox
by (15)
::::; k. X
kx{(w+kx)+(k-kx)(l+ 0;x)} y~oy{(w+~)-(~-k)(1+
0: )}
--------- + y y (w +~)2
= ~r oxkx<w +k) + w(k-k) + y{(w +k)~oy -w(ky -k)}l
ox(w +k,i ox(w +ky?
We get the following full equation
36
We assume in the above equation (17)
. k ' yk· S=--+--
w+kx w+~
Z = [ oxkx(w +k) + w(k-kx)
ox(w+~?
Let us know the changing pattern of capital-labour ratios k·, kx. and ky.
k yk S=--+-->0
W+kx W+~
kx(w +k) w(k--k) oyky(w +k) w(ky-k) = + + y -y ----!..--
(w+kx)2 ox(w+~)2 ox(w+~)2 ox(w+ky)2
by ll{c)
Because, kx ~ k e ky and (k - kJ (ky-kJ > 0, Z is larger than zero (Z > 0)
37
~ = ~ k* > 0 z
(18)
~ = ~~ k* > 0 if k* > 0 ox z
Thus, kx·· ky. and k. have the same sign, whether plus ( +) or minus(-) .
. And, let us kqow the relative ,size of variables k·, ky·· kx.
For that purpose , we work out (Z - S)
Z _ S = kx(w+k) +y oykiw+k) + w(k-kx)(ky-kx) __ k __ _____y!_ (w +~)2 ox(w +~)2 ox(w +~)2 (w +~) w +~ U> +~
=
We reformulate the above equation in the following way:
38
Again, (Z - S)
=
(by 11-c)
1 a w(k-kx)(kx-~)(1--) yk (w+k)(2-l)
ox Y a = ------ + _____ x_ (19)
Then, we get the following results by using (18) and (19)
(i) k. > k. X if ox < 1 and ay ~ ox
( ii) k. < k. X if ax > 1 and ox ~ ay
(iii) k. = k. =~ ifo =a =1 X X y
39
In case (i) Z > S ; in case (ii) Z < S and in case (iii) Z = S,
So far, we tried to know the sizes of the change of capital-labour ratios
(~ ,k· .~) using the elasticities of factor substitution in both industries (ax,ay)
in our limited assumptions.
Using the equations which we have got so far, we try to know the relation
between price ratio (P.) and capital-labor endowment ratio (k.)for the
verification of trade pattern.
From the price ratio equation (10)
r, r,f k 0 x Lx ( x)
-r Lx'f(~)
~ - n L:'f(k)
r -1
p X nx· = = y = y X X = y
px -y nYL;yh(~) r r
n/L/h(~)
r -1 n .. X
= y -r L/h(~)
r -1 nr y
r -1 nr y
= y
r -1-r n Y L .. £(k)
Y X X
r -1-r nx .. L/h(~)
= y = y
We take log on both sides,
logP = logy+ (ry -l)logny- (rx -l)lognx + (rx -rY)logL +rxlog Px
-rylog Py + logf -logh
Totally differentiating and writng in variational form and remembering that nx
and ny.are uni9uely determine~ by rx and ry.
40
P* = (r -r)l:+r p*-r p*+C-h* X y X X y Y
(20)
. We know that the rate of change of price ratio (P*) depends on the variation rate
in the total labor (L *), the labor ratio in X industry ( Px "), the labor ratio in Y
industry ( Py·), productivity in X industry (f"), and productivity in Y industry (h *).
Let us look into (rxPx. - rypy*) in equation (20).
From the full employment equation (12)
k -k p X = ___.:._Y -
~-kx
Let us take the log function and by differentiation.
log Px = log (ky- k) - log (ky - kJ
~-dkx_
ky-~
• dk -dk Px = --'Y __
~-k
= (~~-+ k -k
y
(by 18) ...
(~ .5: _§_ - k) = ox Z
~-k
we define S/Z = m
. . (<y m-kl r~ :y -~ )~ Px = X - X r& k*
~-k ~-~
41
(12)
(12a)
And,
k-k X p =--
y ky -kx
Let us again take the log function
log Py = log (k - kx) - log (ky - kJ
Let's differentiate and with varia~ion form,
• dk -dkx dky -dkx Py = k - ~ - k) - kx
k-k X
k-km = k* X
k-~
We substitute (12a) and (12b) into (rxPx. - ryPy.)
rx(~ aYm-k) = k* __ a..::...x __
ky-k
And (-h. ' f 1dk
X h 1dk
- __ Y = k f'dk X X
f h
(12b)
(20a)
Equation (20) and the subsequent results show that a simple relationship between
p and k, which is the basis for a Heckscher-Ohlin type trade pattern, does not
exist in this model. We have therefore to introduce simplifying assumptions. Let
the elasticity of factor substitution in both industries (ax, ay) be the same and
equal to one (ax = ay = 1), then S equals Z (S = Z) and m = 1, kx* = ky* = k*
follows.
Then, rx Px. - ryPy• is reduced to zero.
r p • - r p • = k • (r - r + r - r ) = 0 xx yy y X X y
The price ratio change (20) is reduced to
P* = (r -r) L • + f* - h • X y
And, we get by (20b)
P*=(r -r)L*+(rxkx- rykylk* X y (A)+~ (A)+~
(21)
If suppose, the return to scale is the same in both industries (rx = ry).
Then, the above p• equation is reduced to
p * : f X x-y y X y k * : f X y k * {
k w + k 1c- - wk - k k } { w(k - k ) }
x (w+kx)(w+~) x (w+~)(w+~) 21(a)
P has the positive relation with k when the capital intensity in X industry is larger
than that of Y industry. So, we know that the traditional Heckscher- Ohlin type ' '
trade pattern is likely to be observed in the above situation.
But, when the returns to scale are not the same in the industries, p* is
determined by both the change of whole labor (L *) and capital labor endowment
ratio (k*)
43
= (r _ r ) L • + x x x x y y y y x y k. - {r k w +r k k - r k w - r k k } X y ((A) + ~) ( (,.) + ~)
(22)
with k • > 0 and L • ~ 0 p• > 0
p· and k • have positive relation if return to scale and capital intensity in X
industry are larger than those of y industry. We know that the Heckscher-Ohlin
type trade pattern is still valid with more constraints than in the traditional
model.
The Heckscher-Ohlin trade pattern is likely to be observed provided that
(i) the returns to scale in the capital- intensive industry is at least as strong as
that in the labour intensive industry and (ii) the capital-abundant country is at
least as large as the labour abundant country in terms of the size of its labour
force.
If, however, k • = 0.
then , p• = (r -r )L • X y (23)
This means that trade between two countries that are identical in relative factor
endowments but different in size is likely to be determined by the returns to scale
44
factor. The larger country is likely to have comparative advantage in the product
whose returns to scale is stronger and the smaller country will have comparative
advantage in the product whose returns to scale is weaker.
The analysis upto this point does not really determine the pattern of trade.
One has to look into the integrated world economy for determining comparative
advantage. Our purpose has been to show that an unambiguous relat~onship
between the autarky price ratio and factor endowment ratio does not e1nerge
unless we assume that ax = ay = 1. In what follows we formulate a model with
Cobb-Douglas production functions and discuss the equilibrium in the integrated
world economy.
45
II. INTEGRATED WORLD TRADE MODEL WITH COBB-DOUGLAS PRODUCTION FUNCTIONS AND INCREASING RETURNS TO SCALE
In the following, we extend the prevwus closed economy into open
economy which includes foreign country and try to know the trade pattern in the
integrated world formulation ori~inated with Dixit and Norman(1980). We use
the Cobb-Douglas production function in place of general production function of
the preceding part of this chapter. The production function of a representative
firm in each of the two industries producing X and Y goods are:
.X = L «xK Px = L "x + P1 ( KXJP• X X X L
X
r. = a. + A.> 1, I I 1-' I i=x,y
(1)
From the X, Y functions, the marginal products of labour and capital may
be written as:
XK = L:•pxk:x-1 ~ = PxL~~-1~.-1 X
(2)
For profit maximization of a representative firm with respect to its factors,
Land K:
46
r = MRx.XK = MRY.Y K
MR ; Marginal Revenue
Factor price ratio in X industry w(kJ
XL w(k) = - =
X X K
Factor price ratio in Y industry U?(ky)
w(~) = YL = ~ ~ YK ~y
Therefore, we get
(3)
3(a)
We follow the same procedure till the equal marginal capital productivity
equation ll(c) at page (34) as there is no difference between the Cobb-Douglas
production function here and the general 'production function except that
f(ki) = ~~1 (i =X,Y)
So,we get from page(34)
(k-~) = y (~ -k)
w+k1 c..>+~ ll(c)
again, y = B/a in Cobb-Douglas Utility Function.
For knowing the relationships between kx , kY' k, we substitute the factor price
ratio equation (3) into ll(c)
47
or
k- k X
or
or
(~ + Y ~)kx = (~~ + Y Pxay)k rx ry rx axry
then,
Px Pxay - +y--
~= rx axry
k = Hk (4) . Px
+ y~ rx rY
Px Pxay - +y --
where H = rx axry
> 0 ' Px p
+ y _L
rx rY
4(a)
48
where , J..
And, the factor price ratio( w) is:
(5)
~. ~.", l -+y--
where, J "x rx axry > 0 =-
Px (~•r!r] rx ry
We come to know that the factor price ratio ( w) and the factor endowment ratio
(k) have the positive relation. When we introduce the world which consists of
only two countries, Home (h) and Foreign Country (f) into our model, we get
K 8 = Kh + Kt
L8 = Lb + Lr
then
g:Global
Kb +Kt Kb Lh Kr Lr k = = -.- + -- = p k + p k
8 L LL LL hh tt g h g f g
Where ph = ~/Lg and Pr = Lr/Lg.
Therefore,
~ ~ kg ~ kc
(6)
Then, we can draw the following straight line through origin between w and k
according to (5)
49
k
Before trying to find the equilibrium price ratio of X.Y goods for the
closed economy, let's find out the labour ratio in X. Y industry ( Px• Py). From the
full employment condition ( 12) at page(33 ), we get.
k -k P - y
x ~-kx
k-k X
Py = --~-kx
by (12)
We calculate
6(a)
J3x J3x«y J3y 1_ P.a,) --+y-- y-
k-~ = k 1 -rx «xry
= k rY «xJ3y
~X J3 J3x J3 --- +y-L + y .:J..
6(b)
IX rY rx ry
k-~ = k 1 6(c)
50
Therefore, the labor ratio in X industry ( pJ is: ' '
Px =
(~ + y Pxcxyl rx CXly
(7)
Px is a constant because all (rx, ay, ~x· .. ) are parameters.
Therefore, Py = 1 - Px = constant also,
Next, we try to know the demand funtions of X.Y goods using Cobb-
Douglas Utility Function.
Again, using Lagrangian from the closed equilibrium model 9(a) at page(32)
(X Dy p X - = p Dx py
or,
Dy p px
=- -D (X p X y
We substitute the above demand DY into the Income equation.
p px Z (Income) = D P + - - DxPy
X X (X p y
51
Then, the demand functions are;
Dx z (X (8)
= --px cx+P
D z _P_ = y py cx+P
We assume the price of X goods as numerate (Px= 1), then, the price ratio(p)•
Then, the demand functions (8) is rewritten as follows.
D=-p_z y
Now, we try to get the national income (Z) from the factor market.
w- rZ=-L+-K
px px
~
Assuming the social Cobb-Douglas utility function and taking factor marginal
productivity with zero profit in the long run (7) at page(32), we get
r xk ~ Lrx-1 kPx-1 -=-Px
X X rx rf
w XL = ~ L:I-l~I = (9) p rx rx X
52
Then, the national income(Z) is;
z = ~ L:·-1~'L + .~x L:·-1~·-1i( rx rx
r -1
= Lr,£ k:'- 1n~·-r·(cxx~ +Pxk) rx
r, -1
= ~HP,-1n~-r·(cxxH+Px)Lr•kp• rx
We rewrite the demand functions Dx DY in the following way.
r1
-1 _ p _ P D = _p_ ~ HP.-1n 1-r.(cx H+P) L r1k 1 =C e•k 1
Y a+ p rx x x x p p
where,
Now, we get the supply functions of X and Y goods
X == n L r,kP. == n 1-r .. (L- )r• kp1 X X X X. X X
where p X
53
by (4)
8(a)
(10)
We've got the demand and supply of both goods.
Then, for Y goods(Dy = Y)
therefore,
pea = .A[<rx-rr>k<P.-P,.> (11)
= closed economy equilibrium price ratio
A > 0
We come to know that in the closed equilibrium, the price ratio depends on
eeuntry size (L) and capital-labour endowment ratio(k). In this model, the price
' ratio is independent of its output. This independence character has also been
shown in many other monopolistic competition models.
ANALYSIS OF INTEGRATED WORLD TRADE MODEL
We assume that the world (G) simply consists of home country (H) and
foreign country (F) and follow the way of what Krugman(1980), Lawrence &
Spiller ( 1983) had done in their integrated trade model. The foreign country
having the identical production functions has a closed economy equilibrium
similar to that, of the home country. And also, the world equilibrium shows the
same structure of relationships as in the home aswell as foreign country closed
equilibrium as if the world is a bigger country than either home or foreign
54
country. The world economy, ,being a closed economy, has perfect mobility of
both goods and factors within itself.
Using the relation between factor price ratio ( w) and factor endowment
ratio (k) in a closed economy from (5) extended to world equilibrium, let's try to
know the relation in our integrated world trade.
(&)h = J kh
h : home country, g : global
Then, we get
(12)
wh- wg = J(kh -kg)>< 0 , as, kh> <kg 12(a)
We know that if home country is capital abundant, the factor price ratio ( w) falls
when trade takes place as in the traditional Heckscher-Ohlin theorem. This of
course, presupposes that the integrated world equilibrium can be taken as the
free trade equilibrium-a proposition which we shall establish later.
Next, we try to know the tendency towards the equilibrium factor price
ratio. From the real factor price equation (9).
W = Closed economy equilibrium wage rate measured m terms of good X
= (XX (Lxtx-1 k:• rx
13(a)
55
Where,
<X 1 r 1 -1Hp• 1-r1 O Jx =- Px nx >
rx r = Closed economy equilibrium profit rate on capital
= HxcLt·-1kP.-1
Where,
= ~ p:·-1n~-\L)r.-1 HP.-1kP.-1 rx
Px r,-1 1-r, p -1 O H =-p n H • >
X X X
rx
13(b)
It may be mentioned here that since the number of producers in each
industry is uniquely determined by the returns to scale parameter, the two
countries as well as the integrated world economy will have the same number of
producers in each industry. It also implies that the degree of industrial
concentration is higher in the world economy than in either of the two counties
in their respective autarky equilibria. This is a special feature of our model which
follows from Cobb-Douglas utility function. But, Lawrence and Spiller(1983) have
used C.E.S. utility function in monopolistic competition model for getting
different results. We write the equilibrium wage rates of home country and world
as follows :
wh = Jx(L)~'-1k:· by 13(a)
w = J (L)r.-1 kP. g X g g (14)
56
When the home country is relatively labour abundant (kg > kh), the world
equilibrium wage rate may be higher than the closed equilibrium rate (Wg > Wh).
Therefore, after trade the real wage rises in the labour abundant country. But,
if the home country is capital abundant (kh > kg), then the sign of (Wh- W,) is
indeterminate and we can not s.ay that the real wage rate falls in a capital
abundant country after trade begins.
Likewise,
by 13(b)
(15)
Since 1 < (ax + .Bx) < 2, we also assume that .Bx < 1.
When the home country is relatively capital abundant (kh > kg ) and (.Bx < 1),
then world equilibrium return on capital may be higher than the closed
equilibrium rate. But, if the home country is labour abundant (kh < k ) and (.B . g X
< 1), then the sign of (rh - rg) is indeterminate. In both cases, a country's
abundant factor experiences an increase in its real reward after trade like in the
traditional Heckscher-Ohlin Theorem. But, nothing definite can be said about its
scarce factor's real reward.
57
THE TRADE PATTERN
We try to know the pattern of trade in the integrated world equilibrium.
From the closed economy equilibrium price ratio (11), we know that the product
price ratio depends on country size (L) and capital-labor endowment ratio (k)
unlike in the constant returns to scale model. We write home country(h) as well
as integrated world(g) equilibrium price ratio like:
ph = A(i)~' -ry k:• -~Y
p = A(i)r,-ry k~.-~,. g g g
(16)
In view of( 6) capital and labour in the integrated economy can be apportioned
between the home and foreign components in which case P g will be the free trade
terms of trade between the two trading countries with no international factor
mobility.
Firstly, let us know the sign of (Bx-By) in the above equation.
From 6(a)
then, Bx ay - ax BY > 0 or, Bx (ry-By) - BY (rx-BJ > 0 or, Bxry > Byfx
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(17)
In other words, Bx and BY are proxies for capital labour ratios in the two sectors
provided that the returns-to-scale parameter is higher in the capital-intensive
sector.
We know from (16) that, when the returns to scale are the same in
both X and Y industry (rx = ry) and home country is relatively capital abundant
(kh > kg), then the integrated price of capital intensive goods (kx > ky, Bx > By)
might be higher than the closed economy equilibrium price (pg < ph). Then the
traditional Heckscher-Ohlin theorem holds.
But, when the returns to scale are not the same in both industries
(rx ,. ry), then the H-0 theorem may not hold. If suppose, the returns to scale in
X industry is stronger than Y industry (rx > ry, kx > kY' Bx > By) and there is no
difference in capital endowment ratios between countries (kh = kg = kr), then the
world integrated equilibrium price of X goods might be lower than that of closed
equilibrium price (Pg > Ph).
Now,let us compare the home equilibrium price ratio with foreign price ratio.
ph = A(L)~'-rY k:x-Py
Pr = A(L);·-rr ki·-Py (18)
If suppose, the home country is simply bigger than foreign country in terms of
population size (Lh > Lr), but both countries have the same capital labour
endowment ratio as before arid (k > k, r > r and B > B) then the price of X y X y X Y'
capital intensive goods in home country (1/Pg) might be lower than that of
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foreign equilibrium price (Ph > Pr). Therefore, we come to know that a country
larger in size will have comparative advantage in the capital intensive goods of
which scale economy is stronger. But in free trade, the price of the product will
decrease in both countries.
1 I 1 -< -<- 18(a) pg ph pf
We assume that this outcome is due to world wide production opportunities of
economies of s~ale. In this mod.el, the smaller country will gain more because it
import goods at cheaper price than autarkic price of import-competing goods and
export the labour intensive goods at a higher price than the autarkic equilibria,
whereas the large country exports at a price less than its autarky price.
Now, we try to explain the pattern of trade using excess demand function.
EDY = world excess demand for Y good(world consumption- world production)
J {L)r~ kll~ (L)r1 1r~1 ] = Ll ~ h + ~ nt - C •[ L~r k:1 + L;r Icir) = 0
Then, we get free trade equilibrit.Im price ratio (Pe)
pe = C(~x~x+L;x~x) (19)
c·~rk:r +L:1 ~1) Substituting the free trade equilibrium price ratio ( 19) into the domestic demand
function of Y goods 8(a), we get home country excess demand of Y good (EDyh)
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EDyh
LrYlr~Y 1+-f~_
~Yk!Y
L;x~x 1+-·--
~·~·
- 1 (20)
If (kr > kh, bJ.It Lr= ~). then, th~ excess demand of Y goods equation(20) is
changed like
EDyh < 0 20(a)
When the size of population is the same in both home and foreign countries
(Lr = L11 ), but the foreign country is more capital abundant than home country
(kr > k11 ), then the excess demand of Y goods at home country might be less than
zero (EDyh < 0), that is, the home country exports the Y goods which are labour
intensive.
Likewise, if(Lh > Lr, but kr = k 11), then again equation (20) is changed like,
( Lf ry - ( Lf r,
Lh Lb
I + ( ~:r > 0' 20(b)
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1