AP HUMAN GEOGRAPHY
UNIT 2 STUDY GUIDE
Population and Migration Patterns and Processes
Everything you need to know for your Unit 2 test —
population distribution, demographic transition, and migration theory, aligned to the official College Board framework.
What's Inside
• 1. Unit Overview & The Big Picture
• 2. Key Concepts (Official College Board Framework)
• 3. Deep Dive: Measuring Population — Density, Distribution & Composition
• 4. Deep Dive: The Demographic Transition Model (DTM)
• 5. Population Growth Formulas & Population Pyramids
• 6. Migration: Push-Pull Theory & Ravenstein's Laws
• 7. Full Vocabulary List — Population & Migration Terms
• 8. Key Theorists, Policies & Case Studies Quick-Reference
• 9. Common Exam Traps & How to Avoid Them
• 10. Practice Questions
1. Unit Overview & The Big Picture
Unit 2, “Population and Migration Patterns and Processes,” covers roughly 12.5–17.5% of the multiple-choice exam
and is a favorite source for the mandatory Data Analysis FRQ, since population pyramids, growth-rate tables, and
demographic data are easy to turn into stimulus material.
Unit 2's throughline: population change is driven by births, deaths, and migration — and every model in this
unit (the DTM, population pyramids, push-pull theory) is really just a different lens for explaining why those
three numbers move the way they do in a given place.
This unit builds directly on Unit 1's spatial concepts (scale of analysis, distribution patterns) and feeds directly into
Unit 4 (Political Patterns) and Unit 6 (Cities), since population change reshapes borders, urban growth, and economic
development.
The 3 Things Your Teacher Wants You to Walk Away Knowing:
• Population distribution and density can be measured multiple ways (arithmetic, physiological, agricultural) and
each measure tells a different story about pressure on land and resources.
• The Demographic Transition Model (DTM) explains how and why birth rates and death rates change together as
a country develops economically — and a country's stage predicts its population pyramid shape and likely
policies.
• Migration is explained by push factors (reasons to leave) and pull factors (reasons to move somewhere), and
these factors can be economic, political, environmental, or cultural/social.
, 2. Key Concepts (Official College Board Framework)
The College Board organizes Unit 2 into eight required topics (2.1–2.8).
Topic 2.1 — Population Distribution
• Physical factors (climate, landforms, water access, soil quality) and human factors (economic opportunity,
transportation, history, government policy) together explain where people live.
• Global population clusters concentrate in East Asia, South Asia, Southeast Asia, and Europe — regions with
fertile land, temperate climates, and long histories of agricultural settlement.
Topic 2.2 — Consequences of Population Distribution
• High density strains infrastructure, housing, and services; low density can limit access to services and economic
opportunity.
• Overpopulation is relative to a region's carrying capacity — the population a given environment can sustainably
support.
Topic 2.3 — Population Composition
• Population pyramids display a population's age and sex structure, revealing growth trends, dependency
burdens, and historical events (wars, baby booms).
• The dependency ratio compares the non-working-age population (under 15 and over 64) to the working-age
population (15–64).
Topic 2.4 — Population Growth and Decline Over Time and Space
• The Demographic Transition Model (DTM) tracks how birth and death rates change across five stages as a
country industrializes and develops.
Topic 2.5 — Population Growth and Decline: Causes
• Death rates typically fall first (due to improved medicine, sanitation, and food supply); birth rates fall later (due
to urbanization, education, and access to contraception), creating a lag that drives rapid growth in the middle
stages.
Topic 2.6 — Consequences of Population Growth and Decline
• Rapid growth strains resources and services in developing countries; population decline/aging (as in Japan)
strains pension systems and shrinks the future workforce.
Topic 2.7 — Effects of Population and Health Policies
• Pro-natalist policies (e.g., France's family subsidies) encourage higher birth rates; anti-natalist policies (e.g.,
China's former One-Child Policy) discourage them.
Topic 2.8 — Causes of Migration
• Push factors drive people away from a place (conflict, poverty, environmental disaster); pull factors draw people
toward a place (jobs, safety, family).
3. Deep Dive: Measuring Population — Density, Distribution & Composition
Density questions on the exam almost always ask you to pick the RIGHT measure for a given claim, not just calculate
one. Know what each measure hides and reveals.
Density Measure Formula What It Reveals
Arithmetic density Total population ÷ total land area A simple population-per-area figure,
UNIT 2 STUDY GUIDE
Population and Migration Patterns and Processes
Everything you need to know for your Unit 2 test —
population distribution, demographic transition, and migration theory, aligned to the official College Board framework.
What's Inside
• 1. Unit Overview & The Big Picture
• 2. Key Concepts (Official College Board Framework)
• 3. Deep Dive: Measuring Population — Density, Distribution & Composition
• 4. Deep Dive: The Demographic Transition Model (DTM)
• 5. Population Growth Formulas & Population Pyramids
• 6. Migration: Push-Pull Theory & Ravenstein's Laws
• 7. Full Vocabulary List — Population & Migration Terms
• 8. Key Theorists, Policies & Case Studies Quick-Reference
• 9. Common Exam Traps & How to Avoid Them
• 10. Practice Questions
1. Unit Overview & The Big Picture
Unit 2, “Population and Migration Patterns and Processes,” covers roughly 12.5–17.5% of the multiple-choice exam
and is a favorite source for the mandatory Data Analysis FRQ, since population pyramids, growth-rate tables, and
demographic data are easy to turn into stimulus material.
Unit 2's throughline: population change is driven by births, deaths, and migration — and every model in this
unit (the DTM, population pyramids, push-pull theory) is really just a different lens for explaining why those
three numbers move the way they do in a given place.
This unit builds directly on Unit 1's spatial concepts (scale of analysis, distribution patterns) and feeds directly into
Unit 4 (Political Patterns) and Unit 6 (Cities), since population change reshapes borders, urban growth, and economic
development.
The 3 Things Your Teacher Wants You to Walk Away Knowing:
• Population distribution and density can be measured multiple ways (arithmetic, physiological, agricultural) and
each measure tells a different story about pressure on land and resources.
• The Demographic Transition Model (DTM) explains how and why birth rates and death rates change together as
a country develops economically — and a country's stage predicts its population pyramid shape and likely
policies.
• Migration is explained by push factors (reasons to leave) and pull factors (reasons to move somewhere), and
these factors can be economic, political, environmental, or cultural/social.
, 2. Key Concepts (Official College Board Framework)
The College Board organizes Unit 2 into eight required topics (2.1–2.8).
Topic 2.1 — Population Distribution
• Physical factors (climate, landforms, water access, soil quality) and human factors (economic opportunity,
transportation, history, government policy) together explain where people live.
• Global population clusters concentrate in East Asia, South Asia, Southeast Asia, and Europe — regions with
fertile land, temperate climates, and long histories of agricultural settlement.
Topic 2.2 — Consequences of Population Distribution
• High density strains infrastructure, housing, and services; low density can limit access to services and economic
opportunity.
• Overpopulation is relative to a region's carrying capacity — the population a given environment can sustainably
support.
Topic 2.3 — Population Composition
• Population pyramids display a population's age and sex structure, revealing growth trends, dependency
burdens, and historical events (wars, baby booms).
• The dependency ratio compares the non-working-age population (under 15 and over 64) to the working-age
population (15–64).
Topic 2.4 — Population Growth and Decline Over Time and Space
• The Demographic Transition Model (DTM) tracks how birth and death rates change across five stages as a
country industrializes and develops.
Topic 2.5 — Population Growth and Decline: Causes
• Death rates typically fall first (due to improved medicine, sanitation, and food supply); birth rates fall later (due
to urbanization, education, and access to contraception), creating a lag that drives rapid growth in the middle
stages.
Topic 2.6 — Consequences of Population Growth and Decline
• Rapid growth strains resources and services in developing countries; population decline/aging (as in Japan)
strains pension systems and shrinks the future workforce.
Topic 2.7 — Effects of Population and Health Policies
• Pro-natalist policies (e.g., France's family subsidies) encourage higher birth rates; anti-natalist policies (e.g.,
China's former One-Child Policy) discourage them.
Topic 2.8 — Causes of Migration
• Push factors drive people away from a place (conflict, poverty, environmental disaster); pull factors draw people
toward a place (jobs, safety, family).
3. Deep Dive: Measuring Population — Density, Distribution & Composition
Density questions on the exam almost always ask you to pick the RIGHT measure for a given claim, not just calculate
one. Know what each measure hides and reveals.
Density Measure Formula What It Reveals
Arithmetic density Total population ÷ total land area A simple population-per-area figure,
