1) The document discusses how external economies of scale can lead to international trade even when countries have identical production possibilities. With external economies, the production possibilities frontier becomes convex, allowing for gains from specialization and trade. 2) It explains that external economies occur when industry-wide costs decrease as industry size increases, due to factors like specialized suppliers. This can result in one country dominating production of a good globally due to lower costs. 3) The document notes that established industries, even if not the most efficient, may remain dominant due to network effects from their head start, illustrating path dependence in trade patterns from external economies.

1. Learning Unit 11
New Trade Model
Part 1: External Economies of Scale
ECON452
International Economics

2. Objectives
1. Recognize why international trade often occurs from increasing
returns to scale
2. Differentiate between internal and external economies of scale.
3. Explain the sources of external economies of scale and how it
affects pattern of trade
4. Descibe the roles of external economies and knowledge spillovers
in shaping comparative advantage and international trade patterns.

3. Introduction
• The models of comparative advantage assumed constant returns to scale:
– When inputs are doubled, output will double as well.
• In developed countries, we observe many industries and firms operating under
increasing returns to scale (economies of scale):
– When inputs are doubled, output will increase by more than double.
– A larger scale is more efficient: the cost per unit of output falls as a firm or
industry increases output.
• Mutually beneficial trade can arise as a result of economies of scale.
– International trade permits each country to produce a limited range of goods
without sacrificing variety in consumption.
– With trade, a country can take advantage of economies of scale to produce
more efficiently than if it tried to produce everything for itself.

4. Two Types of Economies of Scale
• Economies of scale could mean either that larger firms or a larger industry would
be more efficient.
• External economies of scale occur when cost per unit of output depends on the
size of the industry.
• Internal economies of scale occur when the cost per unit of output depends on
the size of a firm.

5. Two Types of Economies of Scale - Example
• There are 10 firms in industry, producing the same quantity (perfect
competition).
• When the industry size doubles (the demand doubles), a number of firms
increases to 20, so each firm is still producing the same quantity. After the
expansion of industry, the average cost of each firm decreases due to external
economies of scale.
• When the number of firms in industry halves, where five firms double output and
maintain the total output of the industry. After the expansion of output of each
firm, the average cost of each firm decreases due to internal economies scale.

6. Reasons for Economies of Scale
• External economies of scale may occur when an expansion of industry result in
more specialized services becoming available at lower cost (e.g. infrastructure
such as road, power line, Internet)
• Internal economies of scale may occur when a firm can spread overhead cost
(e.g. management cost) or large production makes more efficient (e.g. learning
curve).

7. Economies of Scale and Market Structure
• Both external and internal economies of scale are important causes of
international trade.
• They have different implications for the structure of industries:
– An industry where economies of scale are purely external will typically consist
of many small firms and be perfectly competitive.
– Internal economies of scale result when large firms have a cost advantage
over small firms, causing the industry to become imperfectly competitive.

8. Industry Cluster
• Industry cluster: a group of firms in the same industry and related-industries are
concentrated in one geographic area.
– Clusters consist of companies, suppliers and service providers.
• Examples of industry clusters:
– In the U.S., the semiconductor industry is concentrated in Silicon Valley,
investment banking in New York, and the entertainment industry in Hollywood.
– In developing countries, manufacturing industry clusters are observed in China:
One town in China produces most of the world’s underwear, another nearly all
cigarette lighters.
– In India, information services companies are clustered in Bangalore and Mumbai.

9. External Economies and Industry Cluster
• The industry cluster benefits from external economies of scale.
– Concentrating production of an industry in one or a few locations can reduce
the industry’s costs, even if the individual firms in the industry remain small.
• Sources of external economies
– Specialized equipment or services may be needed for the industry, but are
only supplied by other firms if the industry is large and concentrated.
– Labor pooling: a large and concentrated industry may attract a pool of
workers, reducing employee search and hiring costs for each firm.
– Knowledge spillovers: workers from different firms may more easily share
ideas that benefit each firm when a large and concentrated industry exists

10. PPF with External Economies
• Assumption: Two nations have identical
production possibilities frontier and
indifference curves.
• Production possibilities frontier: External
economies (Increasing Return to Scale) makes
PPF convex from the origin (inward-bending).
– As resources are allocated more in one
industry, its output increases at an
increasing rate, while an output of other
goods whose resources are taken decreases
at decreasing rate.
Quantity of Food (QF)
A
Indifference Curve
Quantity of Cloth (QC)
PPF
QC
A
QF
A

11. Equilibrium under Autarky
• At autarky, each country produces and
consumes at A, where each country can
reach the highest indifference curve.
– Each country produces and consumes
QC
A units of cloth and QF
A units of
food.
– The relative price under autarky is a
slope of tangent line at A.
– Since the relative prices are same in
tow countries, neither country has a
comparative advantage to produce
either goods.
Quantity of Food (QF)
A
Indifference Curve
Quantity of Cloth (QC)
PPF
QC
A
QF
A

12. External Economies and Pattern of Trade
• Two countries can gain from specialization and
trade.
• Home specializes to produce cloth at QH, while
Foreign specializes to produce food at QF.
– Choice of specialization is not based on
comparative advantage, but incidental.
• After trade, each country reach Point D at the
highest utility, where DC units of cloth and DF
units of food are consumed.
• Each country is better off as compared with
the autarky at A.
Quantity of Food (QF)
QH
Indifference Curve
Quantity of Cloth (QC)
PPF Slope = -PC/PF
Isovalue Line
QF
D
DF
DCQC
A
QF
A
A

13. External Economies and Pattern of Trade
• Each country may end up with monopoly
due to increasing returns to scale.
• This model explains why we observe large
trades of intermediate goods across
countries.
– Each country specializes to produce
certain parts of the final products to take
an advantage of external economies.
– In the end, all parts are shipped to a
country to be assembled into the final
products with eternal economies.
– Off-shoring and outsourcing keep costs
down in manufacturing.
Quantity of Food (QF)
QH
Indifference Curve
Quantity of Cloth (QC)
PPF Slope = -PC/PF
Isovalue Line
QF
D
DF
DCQC
A
QF
A

14. Model of External Economies
• Model of external economies is
represented by assuming that the larger
the industry, the lower the industry’s
average costs.
• There is a forward-falling supply curve:
the larger the industry’s output, the lower
the price at which firms are willing to sell.
• As in ordinary supply-and-demand
analysis, market equilibrium is at point 1,
where the supply curve intersects the
demand curve, D. The equilibrium level of
output is Q1, the equilibrium price P1.

15. External Economies and Market Equilibrium
• Prior to international trade,
equilibrium prices and output for
each country would be at the point
where the domestic supply curve
intersects the domestic demand
curve.
• Assuming the same technology
(forward-falling supply curves are
same in two countries), due to
greater demand for the products in
China, in the absence of trade, the
price of the product in China,
PCHINA, is lower than the price of the
product in the United States, PUS.

16. External Economies and International
Competition
• When two countries open-up for trade in the
products, consumers in both countries will purchase
cheaper products produced in China.
• The Chinese button industry will expand, while the
U.S. button industry will contract.
• This process feeds on itself: As the Chinese industry’s
output rises, its costs will fall further; as the U.S.
industry’s output falls, its costs will rise.
• In the end, all the products will be produced in China.
• Output rises from Q1 to Q2, leading to a fall in the
price of buttons from P1 to P2, which is lower than the
price of the product in either country before trade.

17. External Economies and International Trade
• Very different from the implications of models without increasing returns.
• In the standard trade model relative prices converge as a result of trade.
– If a cloth is relatively cheap in the home country and relatively expensive in
the foreign country before trade opens, the trade will raise cloth prices in
Home and reduce them in Foreign.
– In the end, both countries produce cloth at the same price which is between
pre-trade prices.
• With external economies, by contrast, the effect of trade is to reduce prices
everywhere.
– Countries drop out from production because they cannot achieve the same
low cost of production.

18. Importance of Established Advantage
• What might cause one country to have an initial advantage from having a lower
price?
• One possibility is comparative advantage due to underlying differences in
technology and resources.
• If external economies exist, however, the pattern of trade could be due to
historical accidents:
– Countries that start as large producers in certain industries tend to remain
large producers even if another country could potentially produce more
cheaply.
– Ex. Silicon Valley, Hollywood, NYC

19. Established Advantage and International
Competition
• Assume that the Vietnamese cost curve (ACVIETNAM) lies
below the Chinese curve (ACVIETNAM) because Vietnamese
wages are lower than Chinese wages.
• At any given level of production, Vietnam could
manufacture goods more cheaply than China. Thus
Vietnam could potentially supply the world market more
cheaply than China.
• If the Chinese industry gets established first, it can produce
and sell goods at the price P1.
• When the Vietnamese industry starts producing the goods,
it costs at C0 (with small production).
• Because the Chinese industry has already established the
market and reached at lower price at P1, the Vietnamese
industry cannot compete.

20. Established Advantage and Pattern of Trade
• Ideally, the country which can produce at cheapest cost should produce and
supply to the world market, then the world economy as a whole benefits.
• However, under external economies once a country establishes the market
and supplies the products to the world market at the low price, even if new
comer can manufacture goods more cheaply, new comer may not be able to
enter the world market and compete with the country.
• No guarantee that the right country will produce a good that is subject to
external economies.
• So a pattern of specialization established by historical accident may persist
even when new producers could potentially have lower costs.

21. Welfare under External Economies – Autarky
or Trade
• Imagine that Thailand could make watches
more cheaply, but Switzerland got there first.
• Thailand imports watches from Switzerland,
which is able to supply the world market
(DWORLD) at a price (P1) low enough to block
entry by Thai producers, who must initially
produce the watches at cost C0.
• If Thailand were to block all trade in watches,
it would be able to supply its domestic market
(DTHAI) at the lower price, P2.
• Trade could make Thailand worse off, creating
an incentive to protect its potential watch
industry from foreign competition.

22. Trade and Welfare under External Economies
• Trade based on external economies has an ambiguous effect on national welfare.
– There will be gains to the world economy by concentrating production of
industries with
external economies.
– It’s possible that a country is worse off with trade than it would have been
without trade: a country may be better off if it produces everything for its
domestic market rather than pay for imports.
• It’s still to the benefit of the world economy to take advantage of the gains from
concentrating industries.
– Each country wanting to reap the benefits of housing an industry with
economies of scale creates trade conflicts.
– Overall, it’s better for the world that each industry with external economies
be concentrated somewhere.

23. Dynamic Increasing Returns
• So far, we have considered cases where external economies depend on the
amount of current output at a point in time.
• But external economies may also depend on the amount of cumulative output
over time.
• Dynamic increasing returns to scale exist if average costs fall as cumulative
output over time rises.
• Dynamic increasing returns to scale could arise if the cost of production depends
on the accumulation of knowledge and experience, which depend on the
production process over time.
• A graphical representation of dynamic increasing returns to scale is called a
learning curve.

24. The Learning Curve
• The learning curve shows that unit cost is lower
the greater the cumulative output of a country’s
industry to date.
• A country that has extensive experience in an
industry (L) may have a lower unit cost than a
country with little or no experience, even if that
second country’s learning curve (L*) is lower—
for example, because of lower wages.

25. Effect of Dynamic Increasing Returns
• Like external economies of scale at a point in time, dynamic increasing returns to
scale can lock in an initial advantage or a head start in an industry.
• Can also be used to justify protectionism.
– Temporary protection of industries enables them to gain experience: infant
industry argument.
– But temporary is often for a long time, and it is hard to identify when external
economies of scale really exist.

26. Economic Geography
• Economic geography: Study of international trade, interregional trade
and the organization of economic activity in metropolitan and rural
areas.
– Economic geography studies how humans transact with each other across space.
– Communication changes such as the Internet, e-mail, text mail, video
conferencing, mobile phones (as well as modern transportation) are changing
how humans transact with each other across space.

27. Disclaimer
Please do not copy, modify, or distribute
this presentation
without author’s consent.
This presentation was created and owned
by
Dr. Ryoichi Sakano
North Carolina A&T State University
Disclaimer
Please do not copy, modify, or distribute
this presentation
without author’s consent.
This presentation was created and owned
by
Dr. Ryoichi Sakano
North Carolina A&T State University