a.k.a. kuby snacks: chapter 4 newton’s first law of migration: the gravity model

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