Population and Migration Review Notes

Population Distribution

  • Learning Objective (2.A.1): Analyze population distribution at different scales.
  • Factors Influencing Distribution:
    • Physical: Climate, landforms, water bodies.
    • Human: Cultural, economic, historical, political.
  • Climate Impact: Population density varies with climate zones (tropical, subtropical, temperate, polar).
  • Landforms Impact: Population density affected by altitude and physical features.
  • Bodies of Water Impact: Proximity to water influences population distribution.
  • Physical Factors Favoring High Density:
    • Access to food, water, shelter.
    • Midlatitudes (30-60° N/S).
    • Moderate climates.
    • Low-lying areas.
    • Large bodies of water.
    • Natural resources.
  • Political Factors:
    • Government policies (e.g., Brazil moving its capital to Brasilia to develop the interior).
  • Economic Factors:
    • Job opportunities (e.g., Norilsk, Siberia for nickel deposits).
  • Cultural Factors:
    • Shared religion or beliefs (e.g., Hinduism in India).
    • Examples between East and West China due to arable land.
    • Density = \frac{Population}{Area}
    • China: High population density (145 people per square kilometer in 2018).

Population Density Types

  • Arithmetic (Crude) Density:

    • Arithmetic Density = \frac{Total Population}{Total Land Area}

  • Physiological Density:

    • Physiological Density = \frac{Total Population}{Total Arable Land}
    • Indicates pressure on arable land.
    • Example: Egypt's high physiological density (8,078/sq. mi) vs. arithmetic density (226/sq. mi).

  • Agricultural Density:

    • Agricultural Density = \frac{Number of Farmers}{Total Arable Land}
    • Reflects agricultural efficiency; influenced by technology and fertile land.
    • Example: Bangladesh and Netherlands (B: 431/sq. mi N: 31/sq. mi)

Population Composition

  • Dependency Ratio:
    • Indicates economic burden; high ratio means more non-working individuals dependent on the workforce.
  • Youth Dependency Ratio:
    • Ratio of population under 15 to the working-age population (15-64).
  • Aging Population:
    • Percentage of population age 65+ increasing globally.
  • Sex Ratio:
    • Sex Ratio = \frac{Number of Males}{Number of Females}
    • Global ratio: 101 males per 100 females; varies by region and affected by factors like childbirth mortality, emigration, war, and cultural preferences.

Population Pyramids

  • Use: Project population growth/decline and predict markets.
  • Structure:
    • Age and sex distribution.
    • Youth dependents, working population, and elder dependents.
  • Periphery Country Pyramid:
    • Wide base, tapers upward indicates high population growth.
  • Core Country Pyramid:
    • Stable
  • Declining Growth:
    • Narrow base, wider upper section.

Demographic Rates

  • Crude Birth Rate (CBR):
    • CBR = \frac{Number of Live Births}{1000 People}
    • Higher in less developed regions.
  • Crude Death Rate (CDR):
    • CDR = \frac{Number of Deaths}{1000 People}
    • Affected by population age structure.
  • Natural Increase Rate (NIR):
    • NIR = \frac{CBR - CDR}{10}
    • Indicates population growth or decline.
  • Infant Mortality Rate (IMR):
    • IMR = \frac{Number of Infant Deaths}{1000 Live Births}
    • Higher in developing regions.
  • Life Expectancy:
    • Average years a person is expected to live; higher in developed countries.
  • Total Fertility Rate (TFR):
    • Average number of children a woman will have (ages 15-49); replacement level fertility is slightly above 2.

Demographic Transition Model

  • Stages:
    • Stage 1: High birth and death rates, stable population.
    • Stage 2: Declining death rates, high birth rates, rapid population growth.
    • Stage 3: Declining birth rates, stabilizing population.
    • Stage 4: Low birth and death rates, stable population.
    • Stage 5: ?

Epidemiological Transition Model

  • Stages:
    • Stage 1: Famine, infectious diseases cause most deaths.
    • Stage 2: Receding pandemic diseases due to improved sanitation.
    • Stage 3: Degenerative diseases (heart disease, cancer) increase.
    • Stage 4: Delayed degenerative diseases due to medical advances.
    • Stage 5: Reemergence of infectious diseases.

Population Theories

  • Malthusian Theory:
    • Population growth (exponential) will outpace food production (arithmetic), leading to starvation.
  • Cornucopian Theory:
    • Population growth stimulates innovation and economic development.

Population Policies

  • Pronatalist:
    • Encourage more births and immigration (e.g., France, Japan, Sweden).
  • Antinatalist:
    • Discourage births (e.g., China's one-child policy).

Women and Demographic Change

  • Lower Fertility Rates:
    • Associated with higher education, working outside the home, access to healthcare and contraception.
  • Higher Fertility Rates:
    • Associated with less education, early marriage, traditional gender roles, limited access to healthcare and contraception.

Population Aging

  • Consequences:
    • Political (conservative voting, elder care issues).
    • Social (importance of staying active).
    • Economic (fewer working-age people to provide taxes).

Laws of Migration

  • Most migration occurs in steps (voluntary/transnational).
  • Every migration flow generates a return or counter-migration.
  • The majority of migrants move a short distance (distance decay).
  • Migrants who move longer distances tend to choose major sources of economic activity.
  • Urban residents are often less migratory than inhabitants of rural areas.
  • Families are less likely to make international moves than young adults.
  • Most migrants are adults (selectivity = characteristics).
  • Large towns grow by migration rather than natural population growth.
  • More long distance migrants are male.
  • More long distance migrants are adult individuals rather than families with children

Migration

  • Push Factors:
    • Negative conditions that cause people to leave (e.g., lack of jobs, environmental disasters, political instability).
  • Pull Factors:
    • Positive conditions that attract people (e.g., economic opportunities, religious freedom).
  • Types of Migration:
    • Voluntary: Migrants relocate by choice
    • Forced: Movers have no choice but to relocate: Slavery, Human Trafficking
      Refugees
      IDP
      Asylum Seekers
  • Refugees:
    • Flee their country due to political, social, or environmental factors.
    • Leading sources: Afghanistan, Palestine, Iraq.
    • Economic impacts: Can strain resources in receiving countries but also contribute to the economy.
  • Guest Workers:
    • Temporary migrants taking jobs in other countries; remittances sent home.
    • Rural to urban
  • Types of Migration:
    • International (Transnational): Movement across international boundaries.
    • Internal: Movement within a country.
    • Emigration: Exiting.
    • Immigration: Entering.
    • Chain: Migrant flows from a common origin to a common destination.
    • Channelized: Migratory patterns common between two points.
    • Forced: Leave Homes for another location.