Title: Lectures 4-5: The specific factors model
1Lectures 4-5 The specific factors model
2Outline
- Introduction
- The specific factors model
- International trade in the specific factors model
- Income distribution and the gains from trade
- The political economy of international trade
policy - Summary
3Introduction
- International trade has important income
distribution consequences within a country. - There are two fundamental reasons for why trade
has important effects on income distribution - Production factors cannot instantaneously
relocate from one sector to another at zero cost.
- Factors demand vary by sector.
- The specific factors model highlights how trade
affects the income distribution.
4The specific factors model
- Assumptions
- The economy produces two goods, manufactured
goods (M) and food (F) - There are three production factors labor (L),
capital (K) and land (T). - Manufactured goods are produced using capital and
labor (but not land). - Food is produced using land and labor (but not
capital). - Thus labor is mobile because it is used by both
sectors - Land and capital are specific factors that can be
used in the production of one good only. - All markets are perfectly competitive.
5The specific factors model
- How much of each good is produced?
- The production of manufactured goods depends on
the quantity of labor and capital used in the
sector. - This relationship is captured by the production
function. - The production function for good X characterizes
the maximum quantity of good X that can be
produced using all possible combinations of
factors. - For example, the production function for
manufactured goods (food) tells us the quantity
of manufactured goods (food) that we can produce
for any given quantity of capital (land) and
labor.
6The specific factors model
- The production function for manufactured goods is
given by QM QM (K, LM) (3-1) - where
- QM is the output of manufactured goods
- K is the endowment of capital
- LM is the number of workers employed in the M
sector - The production function for manufactured goods is
given by - QF QF (T, LF) (3-2)
- where
- QF is the output of food
- T is the endowment of land
- LF is the number of workers employed in the F
sector
7The specific factors model
- The labor market equilibrium under full
employment implies that - LM LF L (3-3)
- We can use these relationships to construct the
production possibility frontier of the country.
8The specific factors model
- The production possibility frontier
- To analyze the production possibility frontier of
the country we need to ask how the output mix of
the country varies as labor relocates from one
sector to the other. - Figure 1 shows the production function for
manufactured goods.
9The specific factors model
Figure 1 The manufactured goods production
function
10The specific factors model
- The shape of the production function highlights
the presence of decreasing marginal product of
labor - Adding an extra worker to the production process,
keeping capital constant, implies a reduction in
the quantity of capital per worker. - Therefore, every additional unit of labor will
imply an increase in output at a decreasing rate. - Figure 2 depicts the marginal productivity of
labor, i.e. the increase of output brought about
by an additional unit of labor.
11The specific factors model
Figure 2 The marginal product of labor
12The specific factors model
Figure 3 The PPF in the specific factors model
Food production function
Production possibility frontier(PP)
Manufactured goods production function
Labor allocation(AA)
13Slope of the PP curve
- Ricardian model
- The PP curve is a straight line because the
opportunity cost of food in terms of
manufacturing is constant - Specific factors model
- The PP curve illustrates the presence of
decreasing marginal productivity of labor in each
sector. The slope is given by - MPLF /MPLM - To increase the ooutput of manufactured goods by
one unit, the economy needs to reduce the output
of food by MPLF /MPLM
14The specific factors model
- Prices, wages and labor allocation
- How much labor will be used by each sector?
- To answer this question, we need to consider the
demand and the supply of labor. - Labor demand
- In each sector, employers will try to maximize
profits, hiring workers up to the point in which
the marginal product of labor is equal to the
cost of hiring that additional unit.
15The firms problem
- In each sector, the firm maximizes profits, i.e.
it solves the following problem
and the corresponding first order condition is
given by
16The specific factors model
- The labor demand curve in the manufacturing
sector is given by - MPLM x PM w
- The wage is equal to the value of the marginal
product in the manufacturing sector. - The labor demand in the food sector is instead
given by - MPLF x PF w
- Once again, the wage is equal to the value of the
marginal product in the manufacturing sector.
17The specific factors model
- In equilibrium, the salary has to be the same in
the two sectors, as a result of the perfect
mobility of labor. - The wage is determined as a result of market
clearing - LM LF L
18The specific factors model
The allocation of labor between sectors
19Labor demand in the food sector
- In equilibrium, the PPF is tangent to the line
whose slope is given by the relative price of
manufacturing in terms of food (with a minus
sign). - The relationship between relative prices and
output levels is given by - -MPLF/MPLM -PM/PF
20The specific factors model
Figure 5 Output in the specific factors model
Slope -(PM /PF)1
21The specific factors model
- What happens to the allocation of labor and the
income distribution if the price of food and the
price of the manufactured goods change? - Two possible scenarios
- Proportional variation in prices
- Change in relative prices
22The specific factors model
Proportional increase in the two prices
PM increases by 10
PF increases by 10
Increase by 10 in the salary
23The specific factors model
- When prices change by the same proportion, there
is no effect in real terms. - The wage (w) increases proportionally with the
prices, and as a result real wages are
unaffected. - The capital- and land- owners real incomes are
also unaffected.
24The specific factors model
- If only PM increases, labor relocates from the
food to the manufacturing sector and the output
level increases in the manufacturing sector,
while it decreases in the food sector. - The wage (w) does not increase as much as PM ,
since employment in the manufacturing sector
increases and thus the marginal productivity of
labor in that sector decreases.
25The specific factors model
An increase in the price of manufacturing by 10
Increase in the relative demand by 10
26The specific factors model
Figure 8 The effect of a change in the relative
price of manufacturing
Solpe - (PM /PF)1
Slope - (PM /PF) 2
27The specific factors model
- Relative prices and income distribution
- Assume that PM increases by 10. Then, we expect
an increase in wages by less than 10, for
example 5. - What is the effect of this increase on the income
of the following three groups? - Workers
- Capital owners
- Landowners
28The specific factors model
- Workers
- The effect is indeterminate. It depends on the
relative importance of the consumption of the two
goods. - Capital owners
- They are better off. The inflow of additional
workers in the manufacturing sector increases the
marginal productivity of capital. - Land owners
- They are worse off. The outflow of workers from
the food sector decreases the marginal
productivity of land.
29The specific factors model
Figure 9 Determining relative prices
PM /PF
QM/QF
30International trade in the specific factors model
- Assumptions
- Assume that both countries (say Japan and the US)
share the same preferences and thus the same
relative demand. - Thus the only source of trade is represented by
differences in the relative supply across
countries. The relative supply might differ
because of - technology
- different endowments of production factors
(capital, labor, land) - We will assume that there are differences in
factor endowments.
31International trade in the specific factors model
- Endowments and relative supply
- What are the effects of an increase in the
capital endowment on the output of manufactured
goods and food? - A country with a large endowment of capital will
produce a higher ratio of manufacturing to food
for every given combination of relative prices.
32International trade in the specific factors model
Figure 10 An increase in the endowment of capital
Increase in the capital stock K
33International trade in the specific factors model
- An increase in the endowment of capital leads to
a shift to the right of the relative supply - An increase in the endowment of land leads to a
shift to the left of the relative supply - What happens if the labor supply increases?
- The effect on the relative output level is
ambiguous, even though we know that both outputs
will increase.
34International trade in the specific factors model
- International trade and relative prices
- Assume that Japan (J) has more capital per worker
than the USA (A). Analogously, the USA have more
land per worker than Japan. - As a result, the relative price of manufactured
goods in autarky is lower in Japan than in the
USA. - International trade brings about a convergence in
relative prices.
35International trade in the specific factors model.
Figure 11 International trade and relative prices
36International trade in the specific factors model.
- The structure of trade flows
- In autarky, production must be equal to
consumption - If trade is possible, the combinations of
manufactured goods and food that are consumed
might differ from those that are produced. - Still, a country cannot spend more than the value
of its output (no borrowing in this model).
37International trade in the specific factors model.
Figure 12 The budget constraint of a trading
economy
Budget constraint (slope -PM/PF)
38International trade in the specific factors model
Figure 13 Equilibrium under free trade
US budget constraint
Japans budget constraint
QAF
DAF
DJF
QJF
39Income distribution and the gains from
international trade
- To assess the effect of trade on income
distribution, we need to remember that
international trade changes the relative good
prices . - International trade improves the welfare of the
specific factor used in the sector producing
export goods, but it reduces the welfare of the
specific factor used in the production of import
competing goods. - International trade has an ambiguous effect on
the mobile factor.
40Income distribution and the gains from
international trade
- It is possible for those who gains from
international trade to compensate those who lose
from it? - If this is the case, international trade is
potentially Pareto improving, i.e. it can make
everybody better off. - International trade increases overall welfare
because it expands the consumption possibility
set. - The expansion of the consumption possibility set
implies that everybody can potentially at least
be made better off as a result of international
trade.
41Income distribution and the gains from
international trade
Figure 14 International trade expands the
consumption possibilities of each country
42The political economy of trade policy a
preliminary look
- International trade creates winners and losers.
- The optimal trade policy
- The government needs to trade off the gains of
some groups against the losses of some other
groups - Some groups ask for protection because they are
already poor (for examples, US workers in the
shoe, apparel industries). - Most economists are still in favor of open trade
policies. - To understand how trade policies come about, we
need to understand the true reasons behind trade
policy choices.
43The political economy of trade policy a
preliminary look
- Income distribution and trade policies
- Usually, those who gain from trade are much less
informed than thos who lose from trade. - Example sugar producers and consumers in the
United States.
44Summary
- International trade has important effects on the
income distribution within a country, thus
creating winners and losers - Income distribution effects are due to
- Production factors cannot relocate costlessly
between one sector and the other. - Changes in the output mix have different effects
on the demand for production factors.
45Summary
- The specific factors model is a useful tool in
the analysis of the income distribution effects
of trade - In this model, differences in factor endowments
might lead to differences in the relative supply
curves and thus lead to international trade. - In each country, specific factors used in the
exporting sectors benefit from opening up trade,
while the specific factors used in the import
competing sectors lose. - The mobile factor, which is used in both sectors,
might gain or lose..
46Summary
- International trade brings about aggregate gains,
which can be used at least as a matter of
principle to compensate the losers, and thus
bring about Pareto gains from trade.