Heckscher-Ohlin Model (focus on 3 diagrams, magnification effect following increase in rel wages, autarky to trade diags, FPE diag (production choice+endowments parallelogram + cone) Flashcards
So what does HO theory say trade occurs due to
Differences in relative factor endowments.
I.e produce goods in which are intensive in the FoP the country is in abundance of.
Factor price equalisation theorem
Trade equalises the real return (wages and rents) across countries.
(Convergence of factor prices)
Stolper-Samuelson theorem
Trade increases the real return (wage or rent) to a country’s relatively abundant factor
But reduces real return to the scarce factor
(Since labour abundant country exports labour-intensive goods. Trade will increase demand for these goods, increasing demand for labour and correspondly wage)
Rybczynski
An increase in a country‘s endowments of one factor will increase output of the good which uses that factor intensively, and reduce output of the other good
(e.g an increase in labour=produce more labour-intensive goods)
(Used in outsourcing in a small country. Explains why wages rise for the domestic country low skill labour. Because outsourcing means there is now more low skill labour available (acts as an increased endowment of lowskill workers) and so sector that uses low-skill labour expands, and increases output.
Assumptions for the HO Model:
2 countries
2 goods
2 factors of production
Production functions identical and CRTS
Factors are mobile between industries (not countries
Factors are homogenous
2 other main key assumptions
Goods differ in factor requirements with no factor intensity reversals (i.e one is capital intensive, one is labour intensive)
Countries differ in relative factor endowments
Production functions
B) We assume marginal product of factors are positive, (adding an additional FOP increases output) … this means what?
X = X (Kx , Lx)
Y = Y (Ky, Ly)
I.e X requires capital K and labour L
B) since MP>0 (positive), means diminishing returns exist.
E.g if capital increases, K/L ratio increases and there is more capital per worker, so dismissing returns to the capital)
VMP (value of marginal product expression)
B) The ratio of marginal products (XL/XK) of labour to capital is equal to what?
C) What is this equation?)
Px x XL = w
Px x XK = r
(Price of product x Marginal product) = VMP
B) The wage to rental rate!
XL/XK = w/r
C) This is the MRTS = XL/Xk = -w/r (isoquant slope=isocost slope) where efficent production (cost minimisation) takes place
Isocost equation
wL + rk = C
Rearrange to make k subject
k = C/r + w/r L
Isocost slope is w/r
Imp:
Condition for efficient factor allocation
B) how to draw efficient production graph pg14 figure 9, with NO FACTOR INTENSITY REVERSALS
w/r = XL/XK = Yl/Yk
Isocost slope = isoquant slope of X = isoquant slope of Y
B) with no FIR
- only one factor intensity line for each good ,
- only one isocost line for both goods
How to draw efficient production WITH FACTOR INTENSITY REVERSALS
With FIR, each good changes their factor intensity i.e X becomes more labour intensive, Y more k intensive.
Also means more than 1 isocost.
General equilibrium 6 equations
2 production functions
X = X(Kx, Lx)
Y = Y(Ky, Ly)
2 full employment conditions
Kbar = Kx + Ky
Lbar = Lx + Ly
2 factor price conditions (factor prices = VMP)
w = XL = PYl
r = Xk = PYk
PYl
PYk are VMPs
Assume we
choose good X as numeraire so Px = 1 Py = P
kx>ky
Cost min diagram pg 14 figure 9
(Tip: draw both factor intensity lines lower down, draw them further apart for the FPE/parallelogram production decisions)
Kx>Ky so Y’s factor intensity line is lower/flatter
Imp: What if we increase RELATIVE wages.
Explain the effect to both cost minimisation diagrams on previous slide
Cost minimisation for X diagram:
Isocost: gets steeper (so isocost can produce less L as more expensive, but also sees an increase in K since capital is relatively cheaper so isocost extends on Y axis)
Factor intensity line: steeper (since using K/L, K increases; since relatively cheaper now). (NO NEW ISOCOST CURVE, JUST MAKE SURE NEW ISOQUANT IS TANGENT TO THE SAME ISOCOST)
Cost minimisation for Y diagram: since Y was labour-intensive, we produce less of it! so
Unlike X, we get a new isoquant tangent to new isocost, to represent less output of Y is now produced
So since relative wages has reduced output of Y (the relatively labour-intensive good) , what happens to the price of Y and why
Price of Y increases (since producing less)
(So good Y uses increases its capital intensity, but also reduces its output since it is still relatively more labour intensive)
Imp: Key result we found of an increase in relative factor prices
(e.g relative wage increase in this instance)
B) key consideration
An increase in the relative factor price will increase the COMMODITY PRICE of the good that uses that factor price intensively
THUS COMMODITY/FACTOR PRICE: POSITIVE REL
B) factor price changes must change by a larger amount than commodity price to maintain equilibirum - Magnification effect later!
Recall condition for efficent factor allocation
w/r = Xl/Xk = Yl/Yk
Wage-rental ratio (isocost slope) = slope of X’s isoquant = slope of Y’s isoquant
(pg 11 figure 6 diagram
Imp: How is there a magnification effect in addition following an increase in relative wages?
Using efficient factor allocaiton equation, as relative wages rise (w/r) , the ratio of marginal products also rise Xl/Xk = Yl/Yk.
P = W/XL (MPL) and so if XL increases, wage must increase by more to maintain equilibrium
Imp:
What happens to rental rates during this upon a increase in relative wages.
see pg 20 to see it
Rental rates fall!
As to consume previous amount X, a’ units of capital is needed. (Now need more of K, which shows a fall in marginal product!!!)
Px = r/MPK (Xk) so if MPK (Xk) falls, r mustve fallen too!
Final magnification effect expression
b) what does this prove
w^>Py^>P^x>r
++ > + > 0 > -
P^x is unchanged following an increase in relative wages
b) Proves Stolper Samuelson holds!