AP HUMAN GEO - Population and Migration

II. Population and Migration

A. Population growth
1. Factors of growth: rates and averages
- Crude Birth Rate (CBR): Number of live births per 1,000 people in a year.
- Crude Death Rate (CDR): Number of deaths per 1,000 people in a year.
- Natural Increase Rate (NIR): Percentage by which a population grows in a year (CBR−CDR)/10(CBR−CDR)/10. Excludes migration.
- Total Fertility Rate (TFR): Average number of children a woman will have through her childbearing years.
- Infant Mortality Rate (IMR): Annual number of deaths of infants under one year of age, compared to total live births.
2. Historical patterns of growth
- For most of history, population growth was slow due to high birth rates being offset by equally high death rates (e.g., famines, diseases).
- Major growth surges occurred with the Agricultural Revolution (ca. 8,000 BC) and especially the Industrial Revolution (1750 onwards), leading to declining death rates.
3. Contemporary patterns of growth
- Global population growth peaked in the 1960s and has since slowed but is still increasing.
- Most population growth is concentrated in less developed countries (LDCs) in Asia, Africa, and Latin America.
- More developed countries (MDCs) often experience low or even negative NIR, leading to aging populations.
4. Demographic transition
- A model describing population change over time via four or five stages, linked to economic development:
- Stage 1 (Low Growth): High CBR, high CDR; very little or no NIR. Pre-industrial societies.
- Stage 2 (High Growth): High CBR, rapidly falling CDR; very high NIR. Industrialization begins, improvements in sanitation, medicine.
- Stage 3 (Moderate Growth): Rapidly falling CBR, moderately falling CDR; moderate NIR. Urbanization, improved status of women, access to contraception.
- Stage 4 (Low Growth): Very low CBR, very low CDR; very little or no NIR (zero population growth). Post-industrial, developed societies.
- Stage 5 (Declining Growth): CDR is higher than CBR, leading to a negative NIR. Increasingly common in some developed countries (e.g., Japan, Germany).
5. Malthusian Theory
- Proposed by Thomas Malthus in 1798. Argued that population tends to grow geometrically (exponentially) while food supply grows arithmetically (linearly).
- Predicted that population growth would eventually outpace food supply, leading to famine, disease, and war (positive checks).
- Advocated for moral restraint (preventative checks) to reduce birth rates.
6. Epidemiological Transition
- Corresponds with the Demographic Transition Model, describing distinct causes of death in each stage:
- Stage 1: Pestilence and famine (infectious and parasitic diseases, Malthusian checks).
- Stage 2: Receding pandemics (improved sanitation, nutrition, medicine reduce infectious diseases).
- Stage 3: Degenerative and human-created diseases (decrease in infectious, increase in chronic non-communicable diseases like cancer, heart disease).
- Stage 4: Delayed degenerative diseases (medical advances extend life expectancy for those with chronic diseases).
- Stage 5 (re-emergence): Infectious and parasitic diseases return or new ones emerge, due to antibiotic resistance, global travel, poverty.
7. Population Policies
- Pronatalist Policies: Encourage births, often to increase labor force or military strength (e.g., France, Russia).
- Antinatalist Policies: Discourage births, often to reduce population growth pressures (e.g., China's former One-Child Policy, India's family planning).
- Eugenic Policies: Favor one racial or cultural group over others (historically, Nazi Germany).
8. Roles of gender and development related to fertility and mortality patterns
- Education of Women: Higher levels of education for women correlate with lower fertility rates (increased opportunities outside home, knowledge of family planning).
- Access to Healthcare: Improved maternal and child health care reduces IMR and overall mortality, influencing fertility decisions.
- Economic Development: As countries develop, economic security often leads to smaller family sizes.
9. Causes and implications of aging populations
- Causes: Declining birth rates (lower TFR) and increasing life expectancy.
- Implications: Strain on social security and healthcare systems, potential labor shortages, increased dependency ratio (more elderly dependents relative to working-age population).

B. Population Distribution
1. Spatial patterns: global, regional, local
- Globally: Population is highly unevenly distributed, with most people living in four major clusters: East Asia, South Asia, Europe, and Southeast Asia.
- Regional/Local: Influenced by physical factors (climate, topography, water access) and human factors (economic opportunities, historical settlement, infrastructure).
2. Demographic trends: case studies
- China/India: High population density and large absolute populations, facing challenges of resource management and urbanization.
- Japan/Germany: Aging populations and declining or slow growth, leading to labor shortages and social welfare strains.
- Sub-Saharan Africa: High growth rates, high youth dependency, and rapid urbanization.
3. Spatial variations in factors of growth
- Birth and death rates vary significantly across different regions, leading to diverse local growth patterns.
- Rural areas often have higher crude birth rates than urban areas due to varying cultural norms and economic needs.
4. Density vs. Distribution
- Population Distribution: The pattern of where people live in an area.
- Population Density: The number of people in a given area. Types include:
- Arithmetic Density: Total number of people divided by total land area.
- Physiological Density: Total number of people divided by the amount of arable land.
- Agricultural Density: Number of farmers divided by the amount of arable land.
5. Impacts of population on the environment and society
- Environmental: Resource depletion (water, fossil fuels), pollution (air, water, land), deforestation, habitat loss, climate change.
- Societal: Strain on infrastructure (housing, transportation, education, healthcare), unemployment, poverty, social unrest.
6. Population pyramids
- Bar graphs showing the age and sex composition of a population. Horizontal bars represent cohorts (groups of ages), with males on the left and females on the right.
- Shape indicates growth patterns: Broad base = rapid growth; narrow base = declining growth; high top = aging population.
- Dependency Ratio: The number of people too young (0-14) or too old (65+) to work, compared to the number of people in their productive years (15-64).

C. Population movement
1. Causes and consequences of migration
- Push Factors: Reasons for people to leave a place (e.g., unemployment, political instability, war, natural disasters, persecution).
- Pull Factors: Reasons for people to be attracted to a new place (e.g., job opportunities, political freedom, safety, better services, family reunification).
- Consequences (Origin): Brain drain, remittance income, reduced pressure on resources.
- Consequences (Destination): Labor force growth, cultural diversity, potential social tensions, strain on infrastructure.
2. Historical migrations with push and pull factors
- Irish Potato Famine (1840s): Push (famine, poverty) leading to migration to the U.S. and other English-speaking countries.
- Transatlantic Slave Trade (16th-19th centuries): Forced migration (push of coercion, pull of labor demand in Americas).
- Great Migration (U.S., early 20th century): Push (segregation, racial violence, economic hardship in South) leading to African American migration to industrial North (pull of factory jobs).
3. Contemporary migrations
- Driven by globalization, economic disparities, political conflicts, environmental change.
- Examples: Labor migration from developing to developed countries, refugee flows from conflict zones (e.g., Syria, Venezuela, Ukraine).
4. Migration to and within the U.S.
- Historical waves: Distinct periods of immigration (e.g., early European, late 19th-early 20th Southern/Eastern European, post-1965 Latin American/Asian).
- Internal Migration: Significant shifts in population within the U.S. (e.g., Rust Belt to Sun Belt due to economic opportunities, climate).
5. Voluntary vs. Forced Migration
- Voluntary Migration: Migrants choose to move, often for economic improvement or personal reasons.
- Forced Migration: Migrants are compelled to move due to political conflicts, persecution, natural disasters, or development projects.
6. Refugee vs. Internally Displaced
- Refugee: Someone who has been forced to flee their country because of persecution, war, or violence, and has crossed an international border.
- Internally Displaced Person (IDP): Someone who has been forced to flee their home but has not crossed an international border; they remain within their own country.
7. Migration Policies
- Immigration Policies: Govern who can enter a country and under what conditions (e.g., quotas, skilled worker programs, family reunification).
- Emigration Policies: Government policies influencing those leaving a country (less common but can include restrictions).
- Guest Worker Programs: Allow foreign laborers to work for a specific period, filling labor shortages.
8. Ravenstein’s Laws
- A set of generalizations about migration patterns proposed by E.G. Ravenstein in the 1880s:
- Most migrants move only a short distance.
- Migration occurs in steps (step migration).
- Long-distance migrants go to major centers of economic activity.
- Rural dwellers are more migratory than urban dwellers.
- Families are less likely to make international moves than young adults.
- Every migration flow generates a return or counter-migration.