chapter 14 Geographical economics

International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Introduction
Objectives / key terms
Zipf's Law
Gravity equation
Cumulative causation
Agglomeration
Multiple equilibria
Stability / optimality
Simulations
Location
Paul Krugman (1953 - )
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Zipf's Law and the gravity equation
20
Delhi
Bombay
ln(size)
15
Calcutta
10
ln( populationi )  16.94 1.048 ln( rank i );
5
( 528.4 )
( 138.4 )
R 2  0.992
0
0
1
2
3
ln(rank)
4
5
6
International Trade & the World Economy;  Charles van Marrewijk
Zipf's Law and the gravity equation
-4
ln(export)-1.033*ln(GDP)
5
Czech R. Austria
Holland
-6
10
Switz.
Belgium
-8
Japan
-10
ln(distance)
ln( exporti )  0.281 1.033 ln( GDPi )  0.869 ln( distancei )
( 0.40)
R 2  0.926
( 34.86)
( 12.77 )
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
T
e
f
Farms in 1
Direction of
(goods and services flows)
d
Spending on m
1-m
manufactures
Farms in 2
Direction of
money flows
Income
(farm labor)
N2 manufacturing firms
N2 varieties (elasticity )
internal returns to scale
monopolistic competition
Spending
on food
b
Farm
workers in 2
Spending (goods)
m Spending on
manufactures
Manufacturing
workers in 2
Income
Spending (goods)
1-m
c
N1 manufacturing firms
N1 varieties (elasticity )
internal returns to scale
monopolistic competition
Spending
on food
(farm labor)
a
Mobility (i)
(labor)
Manufacturing
workers in 1
Income
Farm
workers in 1
Consumers in 2
g
(labor)
Consumers in 1
Income
The
structure
of the
model
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Multiple locations and equilibrium
Total number of laborers; L
(1-)
Laborers in the
food sector (1-)L
1
Laborers in the
food sector in
region 1; 1(1-)L
Note: 1 + 2 = 1
2
Laborers in the
food sector in
region 2; 2(1-)L

Laborers in the
manufacturing sector; L
1
Laborers in the
manufacturing sector
in region 1; 1L
Note: 1 + 2 = 1
2
Laborers in the
manufacturing sector
in region 2; 2L
Mobility
International Trade & the World Economy;  Charles van Marrewijk
Multiple locations and equilibrium
Short-run equilibrium; given the distribution of manufacturing labour
Price index equation



1
1
1 
P1  1W1  2T W2 
 
 locally

imported
 produced

Income equation
I1  1W1  1 (1   )




manufacturing
income
Wage equation (from
demand = supply in
manufactures sector

 1
W1  I1P1
 I 2T
1 /(1 )
food
income
1

 1 1/ 
P2
International Trade & the World Economy;  Charles van Marrewijk
Multiple locations and equilibrium
a. spreading
1
c. agglomerate in region 2
b. agglomerate in region 1
1
1
0
0
0.5
0
region 1
region 2
Three examples
region 1
region 2
region 1
region 2
International Trade & the World Economy;  Charles van Marrewijk
Multiple locations and equilibrium
Manufacturing labour force adjustment
d1

1

change
labor in 1
  ( w1  w );

where w  1w1  2 w2

adj.
wage
speed difference
average real wage
Table 14.2 When is a long-run equilibrium reached?
Possibility 1
Possibility 2
Possibility 3
If the real wage for
All manufacturing workers
All manufacturing workers
manufacturing workers in
are located in region 1
are located in region 2
region 1 is the same as the
(agglomeration in region 1)
(agglomeration in region 2)
real wage for manufacturing
workers in region 2.
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Chapter 14 tool: computer simulations
relative real wage (w1/w2)
1.03
E
F
C
1
D
B
A
0.97
0
0.5
share of manufacturing workers in region 1 (lambda1)
1
International Trade & the World Economy;  Charles van Marrewijk
Chapter 14 tool: computer simulations
relative real wage (w1/w2)
1.1
T = 2.1
T = 1.3
T = 1.7
1
T = 1.7
0.9
T = 1.3
0.0
T = 2.1
0.5
share of manufacturing workers in region 1 (lambda1)
1.0
International Trade & the World Economy;  Charles van Marrewijk
Chapter 14
tool:
computer
simulations
S1
1
1
B
0.5
0
1
S0
Transport costs T
Sustain points
Stable equilibria
Break point
Unstable equilibria
Basin of attraction for spreading equilibrium
Basin of attraction for agglomeration in region 1
Basin of attraction for agglomeration in region 2
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Welfare
Welfare
1
0.98
0.96
0.94
0.98-1
0.96-0.98
0.92
0.94-0.96
0.92-0.94
0.9-0.92
0.9
0.88-0.9
0.833
3
2.5
2.75
transport cost T
2.25
2
1.75
0.433
1.5
1.25
1
0.88
0.033
lambda 1
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Application:
predicting
the location
of European
cities
International Trade & the World Economy;  Charles van Marrewijk
CHAPTER 14; GEOGRAPHICAL ECONOMICS
Introduction
Zipf's Law and the gravity equation
The structure of the model
Multiple locations and equilibrium
Chapter 14 tool: computer simulations
Welfare
Application: predicting the location of European cities
Conclusions
International Trade & the World Economy;  Charles van Marrewijk
Conclusions
Combining various international economic theories with factor
mobility provides a simple theory of location and agglomeration.
Distinction short-run equilibrium (given distribution of the
manufacturing labour force) and long-run equilibrium (endogenously
determined by equality of real wages).
Distinction stable equilibrium and unstable equilibrium.
Using computer simulations:
• high transport costs lead to spreading of economic activity
• low transport costs lead to agglomeration of economic activity
• intermediate transport costs lead to multiple long-run equilibria
Extensions of the basic model can explain empirical regularities, such
as Zipf’s Law and the Gravity Equation.