Title: ECON5335 - International Economics
1ECON5335 - International Economics
- Chapter 4
- Trade Flows in Theory
2Introduction
- Trade models
- - usually question being asked why do we
trade what we trade? - - 3 very simple theoretical models
- - autarky initial position
- - permit trade to occur
- - other question asked is who do we trade
with? - - empirical model based on econometrics
31. Simplest version of the Ricardian Model
- Only two goods
- Meat
- Potatoes
- Only two people
- Rancher
- Farmer
41. Simplest version of the Ricardian Model
- If rancher (R) produces only meat
- and farmer (F) produces only potatoes
- then both have potential to gain from trade
- If both R and F produce both meat and potatoes
- Both can potentially gain from specialization and
trade - Production possibilities frontier (PPF)
- Various mixes of output that economy can produce
if all resources used to capacity
5Figure 1
The Production Possibilities Frontier (a)
Panel (a) shows the production opportunities
available to the farmer and the rancher.
6Figure 1
(b) The farmers production possibilities
frontier
(c) The ranchers production possibilities
frontier
Panel (b) shows the combinations of meat and
potatoes that the farmer can produce. Panel (c)
shows the combinations of meat and potatoes that
the rancher can produce. Both production
possibilities frontiers are derived assuming that
the farmer and rancher each work 8 hours per day.
If there is no trade, each persons production
possibilities frontier is also his or her
consumption possibilities frontier.
71. Simplest version of the Ricardian model
- Specialization and trade
- Farmer specialize in growing potatoes
- More time growing potatoes
- Less time raising cattle
- Rancher specialize in raising cattle
- More time raising cattle
- Less time growing potatoes
- Trade 5 oz of meat for 15 oz of potatoes
- Both gain from specialization and trade
8Figure 2
(a) The farmers production and consumption
(b) The ranchers production and consumption
The proposed trade between the farmer and the
rancher offers each of them a combination of meat
and potatoes that would be impossible in the
absence of trade. In panel (a), the farmer gets
to consume at point A rather than point A. In
panel (b), the rancher gets to consume at point
B rather than point B. Trade allows each to
consume more meat and more potatoes.
9Figure 2
The proposed trade between the farmer and the
rancher offers each of them a combination of meat
and potatoes that would be impossible in the
absence of trade. In panel (a), the farmer gets
to consume at point A rather than point A. In
panel (b), the rancher gets to consume at point
B rather than point B. Trade allows each to
consume more meat and more potatoes.
10Absolute advantage
- Absolute advantage
- Produce a good using fewer inputs than another
producer
11Table 1
The Opportunity Cost of Meat and Potatoes
- Opportunity cost
- Whatever must be given up to obtain some item
- What you give up to get something else
- Measures the trade-off between the two goods that
each producer faces
12Comparative Advantage
- Comparative advantage
- Produce a good at a lower opportunity cost than
another producer - Reflects the relative opportunity cost
- Principle of comparative advantage
- Each good - produced by the individual that has
the smaller opportunity cost of producing that
good - Developed by David Ricardo
13Comparative Advantage
- One person
- Can have absolute advantage in both goods
- By definition, cannot have comparative advantage
in both goods - For different opportunity costs
- One person - comparative advantage in one good
- The other person - comparative advantage in the
other good
14Comparative Advantage
- Gains from specialization and trade
- Based on comparative advantage
- Total production in economy rises
- Increase in the size of the economic pie
- Everyone better off
- Can apply to individuals, firms, and countries
15Comparative Advantage
- Trade can benefit everyone in society
- Allows people to specialize
- The price of trade
- Must lie between the two opportunity costs
- Principle of comparative advantage explains
- Interdependence reliance on other individuals,
firms or countries - Gains from trade applies to individuals, firms
and countries
16Applications of Comparative Advantage
- Should the U.S. trade with other countries?
- U.S and Japan
- Each produces food and cars
- One American worker, one month
- One car, or
- Two tons of food
- One Japanese worker, one month
- One car
- One ton of food
17Applications of Comparative Advantage
- Principle of comparative advantage
- Each good produced by the country with the
smaller opportunity cost of producing that good - Specialization and trade
- All countries have more food and more cars
18What drives comparative advantage in the
Ricardian model?
- In theory
- Clear that there are gains from specialization
and trade that arise from differences in
productivity of labor and capital in each sector - So in Ricardian model if we assume labor is the
only factor of production then labor productivity
would drive comparative advantage and determine
who trades what
aLFQF aLMQM L
19Ricardian model analytics
- If the domestic country wants to consume both
meat and food (in autarky), relative prices must
adjust so that wages are equal in the wine and
cheese industries. - If PF /aLF PM /aLM workers will have no
incentive to flock to either the food or the meat
industry, thereby maintaining a positive amount
of production of both goods. - PF /PM aLF /aLM
- Production (and consumption) of both goods occurs
when relative price of a good equals the
opportunity cost of producing that good.
20Ricardian model analytics
- Suppose that the domestic country has a
comparative advantage in food production its
opportunity cost of producing cheese is lower
than it is in the foreign country. - aLF /aLM lt aLF /aLM
- where notates foreign country variables
- Note here that this is the relative productivity
which therefore determines comparative advantage
21Other models
- Heckscher Ohlin Model (1919)
- Problem with Ricardian model was that it only had
one factor of production - So here a 2 good, 2 FoP model
- Different rule emerges for comparative advantage
- Krugman economies of scale model
- Differentiated products
- Economies of scale
- Different results for comparative advantage
22Factor endowment theory/H-O model
- Look at abundance of FoP or resources
- Country with relatively abundant amount of FoP
will export good or service which is intensive in
that factor - Therefore comparative advantage is in the
relative abundance of the FoP - K/L ratio indicates factor abundance
- If US has K/L 0.5 and China has K/L 0.02 then
US has relatively more K and China relatively
more L
23H-O model
- So China should export good which uses L
intensively, and US should export good which uses
K intensively - So price of K rises in US and price of L falls
- Opposite happens in China price of L rises and
price of K falls - But before in autarky L was paid much less in
China than in the US as so much L in China. - Implication is that there is convergence in
factor prices across countries known as factor
price equalization
24H-O Model
- In Ricardian model no distributional consequences
here they are possible - If US exports more K intensive goods, then income
earned by K goes up (conversely income earned by
L goes down) - Vice versa for China
- Therefore owners of K in US better off compared
with L and v-v for China - Known as the Stolper Samuelson Theory
25Leontief Paradox
- Need to test H-O theory to see if it is true
- Wassily Leontief collected data for US and if H-O
correct US exports should have higher K/L ratio
than imports - (1947) Results US X 14K/L
- US M 18K/L
- Was H-O wrong? Leontief called it a paradox.
- Resolution came from widening defn of K
26Leontief Paradox
By looking at average years of education (human
capital) Baldwin found that greater factor
intensity in exports.
27Krugman model
- Paul Krugman developed a model of trade with
differentiated products. Why? - Here by trading we can expand our market and
lower our costs - But depends on the size and type of economies of
scale - Economies of scale internal?
- Economies of scale external?
- Linders theory of overlapping demands
28Krugman model
- Paul Krugman developed a model of trade with
differentiated products. Why? - Here by trading we can expand our market and
lower our costs - But depends on the size and type of economies of
scale - Economies of scale internal?
- Economies of scale external?
- Linders theory of overlapping demands
29Krugman model
- Given trade begins between 2 countries with
similar industries - We would expect
- Total of firms to fall
- Price to fall as costs fall
- Variety in each country to increase
- Average size of firms to increase
- Ricardian and H-O models explain inter-industry
trade - Krugman explains intra-industry trade
30The Gravity Model
- 3 of the top 10 trading partners with the US in
2011 were also the 3 largest European economies
Germany, UK and France. - These countries have the largest gross domestic
product (GDP) in Europe. - Why does the US trade most with these European
countries and not other European countries?
31Size Matters The Gravity Model (cont.)
- In fact, the size of an economy is directly
related to the volume of imports and exports. - Larger economies produce more goods and services,
so they have more to sell in the export market. - Larger economies generate more income from the
goods and services sold, so people are able to
buy more imports.
32Size Matters The Gravity Model (cont.)
33The Gravity Model
- Other things besides size matter for trade
- Distance between markets influences
transportation costs and therefore the cost of
imports and exports. - Distance may also influence personal contact and
communication, which may influence trade. - Cultural affinity if two countries have cultural
ties, it is likely that they also have strong
economic ties. - Geography ocean harbors and a lack of mountain
barriers make transportation and trade easier.
34The Gravity Model (cont.)
- Multinational corporations corporations spread
across different nations import and export many
goods between their divisions. - Borders crossing borders involves formalities
that take time and perhaps monetary costs like
tariffs. - These implicit and explicit costs reduce trade.
- The existence of borders may also indicate the
existence of different languages (see 2) or
different currencies, either of which may impede
trade more.
35The Gravity Model (cont.)
- In its basic form, the gravity model assumes that
only size and distance are important for trade in
the following way - Tij A (Yi Yj)/Dij
- where
- Tij is the value of trade between country i and
country j - A is a constant
- Yi the GDP of country i
- Yj is the GDP of country j
- Dij is the distance between country i and country
j
36The Gravity Model (cont.)
- In a slightly more general form, the gravity
model that is commonly estimated is - Tij A x Yia x Yjb /Dijc
- where a, b, and c are allowed to differ from 1.
- Perhaps surprisingly, the gravity model works
fairly well in predicting actual trade flows, as
the figure above representing USEU trade flows
suggested.
37Distance and Borders
- Estimates of the effect of distance from the
gravity model predict that a 1 increase in the
distance between countries is associated with a
decrease in the volume of trade of 0.7 to 1. - Besides distance, borders increase the cost and
time needed to trade.
38Distance and Borders (cont.)
- Trade agreements between countries are intended
to reduce the formalities and tariffs needed to
cross borders, and therefore to increase trade. - The gravity model can assess the effect of trade
agreements on trade does a trade agreement lead
to significantly more trade among its partners
than one would otherwise predict given their GDPs
and distances from one another?
39Distance and Borders (cont.)
- The US has signed a free trade agreement with
Mexico and Canada in 1994, the North American
Free Trade Agreement (NAFTA). - Because of NAFTA and because Mexico and Canada
are close to the US, the amount of trade between
the US and its northern and southern neighbors as
a fraction of GDP is larger than between the US
and European countries.
40Distance and Borders (cont.)
41Distance and Borders (cont.)
- Yet even with a free trade agreement between the
US and Canada, which use a common language, the
border between these countries still seems to be
associated with a reduction in trade. - So Canadian provinces trade more with each other,
than with US states, ceteris paribus
42Distance and Borders (cont.)
43Distance and Borders (cont.)
44Gravity model
- Shows that still more likely to trade if no
borders - But also shows that size and geography also
matter - Gravity model tested extensively in economics
literature - Shows that USs natural trade partner is Canada
and to a lesser extent Mexico