2.10

• migration - the movement of people from one place to another
• voluntary migration - people move to a new country of their own free will
• push factor - a factor that encourages people to leave an area, such as poverty, war, famine, or persecution
• pull factor - a factor that attracts people to a place, such as a job or a better quality of life
• immigrant - a person who has moved to a new country to live permanently
• emigrant - a person who leaves their country of origin to live in another country, especially for economic reasons
• migration transition model - a model that describes the stages of migration from a country of origin to a country of settlement
• intervening obstacles - barriers that make reaching their desired destination more difficult
• intervening opportunities - opportunities en route that disrupt their original migration plan
• distance decay - the further apart two places are, the less likely it is that people will migrate between those places
• gravity model of migration - the model assumes that the size and distance between two cities or countries will influence the amount of interactions that include migration, travel, and economic activity
• counter migration - each migration flow produces a movement in the opposite direction
• return migration - immigrants moving back to their former home