a.k.a. kuby snacks: chapter 4 newton’s first law of migration: the gravity model
DESCRIPTION
…Migration A permanent change in residence to outside one’s community of origin. Occurs at various spatial scales: rural-to-urban urban-to-urban global (between countries)TRANSCRIPT
A.K.A. Kuby Snacks: Chapter 4
Newton’s First Law of Migration:The Gravity Model
Places are connected through spatial interaction…the more connected…the more we get…???ideas
information
money
products
people
…Migration
A permanent change in residence to outside one’s
community of origin.
Occurs at various spatial scales:
rural-to-urban
urban-to-urban
global (between countries)
Where to and Why for??Factors of Place Desirability?
(p. 88)
Less-desirable places
More-desirable places
What are some of the "more-desirable places" to migrate to within your state, country, world?...Why??
What are some of the "less-desirable places" to migrate to within your state, country, World?...Why
remittances
immigration = migration across an international border
1850186018701880189019001910192019301940195019601970198019902000
0
2,000,000
4,000,000
6,000,000
8,000,000
10,000,000
12,000,000
14,000,000
16,000,000
18,000,000
AfricaSE Europe
Latin America
No Data
Birthplace for foreign born population shows Historical immigration trends
U.S. immigration laws historically favored northwestern Europeans and excluded people from other regions in the world…Can you tell when those laws changed?
Illegal immigration?? Push and Pull factors??
refugees immigrate unwillingly due to persecution in their home country
(a PUSH factor)
PUSH factorsPULL factors
Others??
better job
pleasant physical setting
affordable housing
desirable climate
proximity to family
high housing costs
traffic gridlock
rising crime rates
War
high tax rates
poor climate
undesirable job
Migrant Selectivity
Figure 4.4 (p. 92)
Distance Decay/Friction of Distance
How has the friction of distance changed since a century ago? Why?
Migration Streams
Migration Streams&
Counterstreams
Figure 4.7 (p. 95)
Ten Largest Domestic Migration Streams of
Persons Born in Cuba
Ten Largest Domestic Migration Streams of
Persons Born in Mexico
Mobility
• Part of American experience
• Mobility is high in developed countries with immigrant background
• Migration in the past as a predictor of future migration.
Figure 4.9 (p. 99)
Moving to a new home is a common sight in the highly mobile United States…Why…When does mobility increase??? Decrease??
U.S. Mobility Rates…Why are we becoming less mobile?
Figure 4.10 (p. 100)
• Regional and sub-regional shifts in population
• Net migration
• Migration patterns reflect:- location of states- historical patterns of movement- changing economic geography- perceptions about places
Net migration rates by state…What explains the differences?
Gravity Model: Predicting Migration
(p. 97)
Are there other variables than size and distance that affect migration decisions?...k is used to smooth out the effects of those other variables
Gravity Model Scatter Diagram
Online Activity
Figure 4.13 (p. 107)
Figure 4.14 (p. 108)
Extreme values to delete and outliers to label
Cluster of points expands when extreme values are deleted
Newton’s First Law of Migration:The Gravity Model
Chapter 4
Case StudyRemember your Homework for Friday
Read Kuby pp. 88-102 and respond to Questions 1-8You will complete the Computer activities in class on Friday
And submit your responses to Activities 1-4 on Monday.
Name That Key Term
A person who is outside his or her country due to a well-founded fear of persecution and who is unable or unwilling to return.
Refugee
A permanent change in residence to outside one’s community of origin. Migration
A move across international borders.
Movements of ideas, information, money, products, and people between places. Spatial Interaction
Immigration
A well-defined migration channel from a specific origin to a particular destination. Migration Stream
Migration that runs opposite to a migration stream. Migration Counterstream
Reasons to move from a particular place. Push FactorsReasons to move to a particular place. Pull Factors
The percentage gain or loss of population due to migration. It is calculated as in-
migrants minus out-migrants divided by the total population, all times 100.
Positive numbers indicate net gain; negative numbers indicate net loss.
Net Migration Rate
The tendency for certain types of people to migrate. Age, education, and other sociodemographic characteristics are
________ ________ factors.
Migration Selectivity
Money sent by immigrants from host country to home country. Remittances
A point on a scatter diagram that is roughly in line with the main trend but is separated from the main group of points
because of its very high or low value.
Extreme Value
A scatter of dots showing the relationship between two variables. Each dot on the
graph represents the x and y coordinates of a different observation or case.
Scatter Diagram
A model to predict spatial interaction, where size (population) is directly
related to interaction and distance is inversely related to interaction.
Gravity Model
The declining intensity of an activity with increasing distance from its point of origin. Distance Decay
The difference between an actual observed value of some variable and its predicted value using the gravity model.
Residuals
Point on a scatter diagram that lies far off the trend line. ________ on the graph correspond to cases that are poorly
predicted by the model. ________ are not to be confused with extreme values,
which may lie far from any other point but which are still close to the best-fitting line.
Outlier