Overview
This lecture reviews all major concepts from Unit 2 of AP Human Geography, covering population distribution, density, composition, demographic models, migration, and policies affecting population trends.
Major Population Clusters and Distribution
- Four major population clusters: South Asia, East Asia, Southeast Asia, and Europe.
- Settlement location is influenced by physical (climate, resources) and human (economic, political, cultural) factors.
- Population distribution can be dispersed (spread out) or clustered (concentrated).
Population Density Types
- Arithmetic density: total population divided by total land area.
- Physiological density: population divided by arable land area.
- Agricultural density: number of farmers divided by arable land.
Impact of Density and Distribution
- High density areas have more political power and economic opportunities but higher taxes/cost of living.
- High density may mean less green space, greater environmental impact, and risk of exceeding carrying capacity.
- Social consequences include better access to services in dense areas but more community in dispersed areas.
Population Composition and Pyramids
- Population composition: age, gender, ethnicity, education, income, occupation.
- Population pyramids show age/sex structure and inform about trends, challenges, and dependency ratios.
- Dependency ratio: number of dependents (young/elderly) per working-age population.
Demographic Measures and Trends
- Crude birth rate (CBR): births per 1000 people/year; crude death rate (CDR): deaths per 1000 people/year.
- Natural increase rate (NIR): CBR minus CDR.
- Total fertility rate (TFR): average children per woman; 2.1 is replacement rate.
- Infant mortality rate (IMR): infant deaths per 1000 live births.
- Factors affecting rates: health care, education, economic development, gender roles, political policies.
Models: DTM & Epidemiological Transition
- Demographic transition model (DTM): five stages from high CBR/CDR (stage 1) to negative NIR (stage 5).
- Epidemiological transition: stages of dominant causes of death, from infectious diseases to degenerative diseases and back.
Malthusian Theory and Critics
- Malthus: population grows exponentially, food arithmetically, leading to catastrophe.
- Neo-Malthusians extend concerns to all natural resources.
- Critics argue technological advances allow food/resources to keep up.
Government Policies and Women’s Roles
- Pronatalist policies encourage more births; anti-natalist policies limit births.
- Policies affect migration and growth; migration policies based on economic/cultural needs.
- Increased economic development and women’s education reduce TFR and IMR.
Migration Patterns and Theories
- Ravenstein’s laws: most migration for economic reasons, mostly short distance, step migration, urban migration.
- Gravity model: migration flows depend on population size and distance.
- Types: forced vs voluntary, refugees vs internally displaced persons, chain, step, guest workers, transhumance, intra/inter-regional.
Push and Pull Factors
- Economic, political, social, and environmental push/pull factors influence migration.
- Emigration = exit; immigration = in.
Migration Effects
- Political debates on quotas, citizenship, and policies.
- Economically, immigration increases skills but emigration can cause brain drain.
- Cultural impact: acculturation, assimilation, syncretism, diversity, and possible anti-immigrant sentiments.
Key Terms & Definitions
- Population Density — Measure of people per unit area (arithmetic, physiological, agricultural).
- Population Pyramid — Bar graph showing age and sex structure of a population.
- Dependency Ratio — Ratio of dependents to working-age population.
- Demographic Transition Model (DTM) — Model explaining changes in birth, death, and growth rates.
- Malthusian Theory — Prediction that population growth will outpace food/resource production.
- Pronatalist Policy — Government action encouraging higher birth rates.
- Anti-natalist Policy — Government action reducing birth rates.
- Push/Pull Factors — Reasons for migration due to conditions at home (push) or in destination (pull).
- Ravenstein’s Laws — General rules about migration behavior.
- Refugee — Person forced to flee their country due to conflict/persecution.
- Brain Drain — Emigration of skilled workers from a country.
Action Items / Next Steps
- Complete study guide practice problems on population density and population pyramids.
- Review and break down different population pyramids and connect them to real-world cases.
- Take the unit practice quiz to test your understanding before the AP exam.