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Unit 2 Essentials

25 must-know vocabulary terms and the 4 big ideas anchoring Unit 2: Population & Migration.

Unit 2: Population & Migration🏠 Unit Hub📁 Flashcards🗺 Cheat Sheet⭐ The Essentials🎙 Podcast🎨 Visual Review📝 MC Practice✍ SAQ Practice
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Demographic Transition Model (DTM)
Five-stage model showing how birth rates, death rates, and population growth change with economic development.
Population Models
Total Fertility Rate (TFR)
Average number of children born per woman during her reproductive years; 2.1 = replacement level.
Population Measures
Natural Increase Rate (NIR)
Birth rate minus death rate; measures population growth excluding migration.
Population Measures
Crude Birth Rate (CBR)
Number of live births per 1,000 people per year — a basic measure of fertility.
Population Measures
Crude Death Rate (CDR)
Number of deaths per 1,000 people per year — influenced by age structure and healthcare.
Population Measures
Population Pyramid
Age-sex diagram showing population distribution; shape reveals growth trends — wide base = growing.
Population Tools
Carrying Capacity
Maximum population an environment can sustainably support given available resources.
Population Theory
Dependency Ratio
Ratio of non-working population (youth + elderly) to working-age population; high ratio = economic strain.
Population Measures
Epidemiological Transition Model
Model showing how primary causes of death shift from infectious to chronic diseases with development.
Population Models
Overpopulation
When a region's population exceeds what its resources can sustainably support.
Population Theory
Push Factor
Condition that drives people away from a place (conflict, poverty, drought, persecution).
Migration
Pull Factor
Condition that attracts people to a destination (jobs, safety, family networks, political freedom).
Migration
Voluntary Migration
Movement based on personal choice, usually for economic or social reasons.
Migration
Forced Migration
Movement compelled by conflict, persecution, or disaster; includes refugees and asylum seekers.
Migration
Chain Migration
Pattern where migrants follow paths established by earlier migrants from the same origin.
Migration
Step Migration
Migration occurring in stages — rural to small town to large city — rather than all at once.
Migration
Intervening Obstacle
Physical, economic, political, or legal barrier that discourages or prevents migration.
Migration
Remittances
Money sent by migrants to family in their home country; a major income source for developing nations.
Migration
Refugee
Person forced to flee their country due to persecution, conflict, or violence; protected under international law.
Migration
Internally Displaced Person (IDP)
Person forced from their home but remaining within their own country's borders.
Migration
Transnationalism
Maintaining social, economic, and cultural ties to one's home country while living abroad.
Migration
Guest Worker
Migrant permitted to work temporarily in a foreign country, usually without a path to permanent residence.
Migration
Net Migration Rate
Difference between immigrants and emigrants per 1,000 people; positive = gaining, negative = losing population.
Migration
Ravenstein's Laws of Migration
19th-century principles that most migrants move short distances, migration occurs in steps, and economic motives dominate.
Migration Theory
Pro-natalist / Anti-natalist Policy
Pro-natalist policies encourage higher birth rates; anti-natalist policies discourage births to slow population growth.
Population Policy
Big Idea 1
Population is unevenly distributed — and geography explains why
Most of the world's 8 billion people live in a few densely populated clusters: East Asia, South Asia, Europe, and eastern North America. Physical geography (climate, terrain, water), history, and economic opportunity all explain these patterns. Understanding where people do NOT live — the ecumene — is equally important.
DistributionDensityEcumene
Big Idea 2
The Demographic Transition Model reveals development patterns
Countries move through predictable stages of population change as they develop economically — from high birth/death rates to low birth/death rates. Understanding where a country sits in the DTM explains its population challenges, policy needs, and future trajectory. The model's limitations matter too.
DTMDevelopmentPolicy
Big Idea 3
Migration reshapes populations, economies, and cultures
Migration is one of the most powerful forces in human geography. It transfers labor, remittances, and cultural practices across borders. Understanding push/pull factors, migration streams, intervening obstacles, and the consequences of migration in both origin and destination countries is central to AP Human Geography.
MigrationPush-PullConsequences
Big Idea 4
Population policies reflect political values and demographic realities
Governments respond to population trends with policies — pro-natalist (encouraging births), anti-natalist (discouraging births), or migration-focused. These policies reflect both demographic needs and political ideologies, and often have unintended consequences (e.g., China's one-child policy creating gender imbalance).
PolicyNatalismGovernment