Chapter 4 Key Terms
Asylum Seeker: Individual seeking refuge in a state as a result of political persecution
Distance Decay: The declining intensity (y) of an activity with increasing distance (x) from its point of origin.
Extreme Value: 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 extremely high or low value. Contrast with outlier.
Gravity Model: A model to predict spatial interaction, where size (population) is directly related to interaction and distance is inversely related to interaction. Assumes:
Population size: realties to degree of spatial interaction
"More people means more migration"
Distance: is inversely related to spatial interaction
"Further away means you are less likely to migrate there"
Immigration: A move across international orders.
Migration: A permanent change in residence to outside one’s community of origin.
Migration Counter-stream: Migration that runs opposite to a migration stream.
Migration Selectivity: The tendency for certain types of people to migrate. Age, education, and other sociodemographic characteristics are migration selectivity factors.
Migration Stream: A well-defined migration channel from a specific origin to a particular destination.
Migration to US Over Time:
1850's - 1900's
North/Western Europeans (Great Britain, France, Sweden, Netherlands)
Established streams from colonial period
Industrial Revolution - Surplus labor
Late 1800's (1882)
First discriminatory laws (Who gets in and who doesn't)
Chinese workers on Union Pacific Railroad
Migration streams: San Francisco and Mexico
1900's - 1930's
East/Southern Europeans
Additional discriminatory laws: 1921 and 1924 quotas
1942- 1963
Bracero Treaty
Mexican migration into the US
Japanese internment & WWII
Demand for agricultural workers
Circumstances' of Mexican workers
Mobility Governance: Countries govern mobility as a mean of security / controlling territory & encouraging economic prosperity
Net Migration Rate: 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.

Outlier: Point on a scatter diagram that lies far off the trend line. Outliers on the graph correspond to cases that are poorly predicted the model. Outliers are not to be confused with extreme values, which may lie far from any other point but which are still lose to the best-fitting line.

Pull Factors: Reasons to move to a particular place.
Examples:
Political freedom
Economic opportunity
Religious tolerance
Push Factors: Reasons to move from a particular place.
Examples:
Climate causing you to move -- too hot, too cold, too dusty
War
Famine or Disaster
Persecution
Poverty
Refugee: 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.
Remittances: Money sent by immigrants from host country to home country.
Residuals: The difference between an actual observed value of some variable and its predicted value using the gravity model.
Scatter Diagram: 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.
Spatial Interaction: Movements of ideas, information, money, products, and people between places.
Undocumented Migrant: Any individual who enters a country without proper authorization.