Population and Migration Review Notes

Population Distribution and Density

  • Population Distribution:

    • Refers to how people are spread out across a given area.

    • Influenced by factors such as:

      • Climate

      • Landforms

      • Water bodies

      • Culture

      • Economics

      • History

      • Politics

    • Site (absolute location with physical characteristics) and situation (relative location and connections) impact settlement locations.

  • Population Density:

    • Refers to the number of people living in a specific area.

    • Three key densities to understand:

      • Arithmetic Density

      • Physiological Density

      • Agricultural Density

Arithmetic Density

  • Definition: Total population divided by total land area.

    • ArithmeticDensity=TotalPopulationTotalLandAreaArithmetic Density = \frac{Total Population}{Total Land Area}

  • Represents basic population density.

Physiological Density

  • Definition: Total population divided by arable land.

    • PhysiologicalDensity=TotalPopulationArableLandPhysiological Density = \frac{Total Population}{Arable Land}

  • Arable land: Land suitable for farming or agricultural production (land with nutrients for growing crops).

  • Significance:

    • Low physiological density: Suggests less environmental stress, easier food production per unit of arable land, reduced reliance on imports.

    • High physiological density: Indicates more pressure on land resources to feed the population, potential need for imports.

  • Example:

    • Country 1: Physiological density of 250 (feeds 250 people per unit of land).

    • Country 2: Physiological density of 2 (feeds 2 people per unit of land).

Agricultural Density

  • Definition: Number of farmers divided by arable land.

    • AgriculturalDensity=NumberofFarmersArableLandAgricultural Density = \frac{Number of Farmers}{Arable Land}

  • Significance:

    • Low agricultural density: Indicates efficient agricultural practices, technology use, allowing people to work in other sectors.

    • High agricultural density: Suggests less efficient techniques, more farmers needed per unit of land, possibly due to less technology.

  • Connection to Economic Development:

    • Less economically developed countries (lower on the demographic transition model, Rostow's model) typically have a higher agricultural density due to more jobs in the primary sector.

    • As economic development increases, agricultural density decreases as people move into secondary, tertiary, quaternary, and quinary sectors.

Carrying Capacity

  • Definition: The maximum number of individuals that an environment can sustain.

  • Impact:

    • Exceeding carrying capacity can lead to consequences related to population distribution, influencing political factors (laws, taxes), economic factors, and social pressures.

  • Consequences of Population Distribution and Density:

    • Densely populated urban areas: More services, healthcare, public transportation, but also more stress and traffic.

    • Dispersed rural areas: More green spaces, less traffic, but potentially less access to services and more driving.

    • Consequences can be positive or negative.

Sex Ratio

  • Definition: The ratio of males to females in a population.

    • Sex ratio under 100: Fewer males than females.

    • Sex ratio over 100: More males than females.

    • Sex ratio of 100: Equal number of males and females.

  • Changes Over Time:

    • As societies age, the sex ratio tends to shift because men generally engage in more risky behaviors and have shorter lifespans than women.

Dependency Ratios

  • General Dependency Ratio:

    • Includes child dependency ratio and elderly (age) dependency ratio.

    • Focuses on the proportion of people not in the labor force compared to those who are.

  • Elderly Dependency Ratio:

    • Focuses on the number of retired individuals compared to the working population.

    • High ratio: The working population bears a higher burden, potentially leading to higher taxes, labor shortages, and social shifts (e.g., more families caring for elderly relatives).

  • Child Dependency Ratio:

    • Focuses on the number of children too young to work compared to the working population.

    • High ratio: Increased need for preschools, daycare, and support for working parents.

Aging Societies

  • Characteristics and Impacts:

    • Decreasing population.

    • Increased need for elderly homes.

    • Government shifts in funding priorities.

    • Changes in voting patterns and political priorities.

    • Decreasing birth rates.

    • Fewer people working, leading to decreased tax revenue.

    • Increased medical costs.

    • Potential implementation of pronatalist policies.

Population Pyramids

  • Graphical representation of a population's age and sex composition.

  • Key Components:

    • Cohorts: Age groups (e.g., 0-4, 5-9).

    • Population: Expressed in millions or percentages.

    • Title, legend, and keys: Essential for understanding the data.

  • Sections:

    • Pre-reproductive years: Ages 0-14 (not yet having children).

    • Reproductive years: Ages 15-44 (childbearing years, primary workforce).

    • Post-reproductive years: Ages 45+ (no longer having children).

  • Interpretation:

    • Large base: Indicates high birth rate, characteristic of Stage 2 countries.

    • Large top: Indicates an aging population, potential population decrease.

    • Insight into dependency ratios: Wide base implies high child dependency ratio; wide top implies high elderly dependency ratio.

    • Sex ratios can be observed.

  • Examples:

    • Italy (2018): Aging population, more people in post-reproductive years.

    • Germany: Shrinking population, more services in tertiary sector, future workforce issues.

Population Dynamics

  • Key Terms:

    • Crude Birth Rate (CBR): Total number of births.

    • Crude Death Rate (CDR): Total number of deaths.

    • Rate of Natural Increase (RNI): CBR minus CDR (migration not factored in).

      • RNI=CBR−CDRRNI = CBR - CDR

    • Total Fertility Rate (TFR): Average number of children a woman will have.

    • Infant Mortality Rate (IMR): Total number of deaths under one year of age.

    • Doubling Time: Time it takes for a population to double.

Demographic Transition Model (DTM)

  • A model that describes population change over time as a country develops economically.

  • Stage 1:

    • High birth and death rates that are roughly equal; low total population with little growth.

    • Jobs primarily in the primary sector; subsistence farming.

  • Stage 2:

    • Death rate declines due to industrial and medical revolutions; birth rate remains high, leading to significant population growth.

    • People expect many children die so birth rates remain high.

  • Stage 3:

    • Birth rate starts to decline as people realize they are living longer; women gain more opportunities; urbanization increases; population growth slows.

  • Stage 4:

    • Low birth and death rates, approaching zero population growth (ZPG); countries may implement pronatalist policies to encourage births.

  • Stage 5:

    • Birth rate falls below death rate, leading to population decline; highly developed countries with fewer children.

Epidemiologic Transition Model

  • Closely connected to the Demographic Transition Model, focusing on causes of death in each stage.

  • Stage 1:

    • High death rates due to animal attacks, famine, and parasitic diseases.

  • Stage 2:

    • Receding pandemics due to improved sanitation and nutritious foods.

  • Stage 3:

    • Degenerative diseases such as cancer, heart disease, stroke, and Alzheimer's become more prevalent as people live longer.

  • Stage 4 to 5:

    • Potential Causes:

      • Disease evolution (e.g., antibiotic resistance).

      • Increased poverty and urbanization.

      • Globalization (spread of disease).

      • Re-emergence of parasitic and infectious diseases.

Malthusian Theory

  • Thomas Malthus argued that population grows exponentially while food production increases arithmetically, leading to resource scarcity and famine.

  • Neo-Malthusians expand this theory to include other resources, arguing that the Earth has a limited carrying capacity and overpopulation leads to environmental issues, shortages, and instability.

Government Policies

  • Pronatalist Policies:

    • Aim to increase birth rates through economic incentives, propaganda, and reduced economic burden.

  • Antinatalist Policies:

    • Aim to decrease birth rates, such as China's One-Child Policy.

  • Immigration Policies:

    • Quotas: Limits on the number of immigrants allowed into a country.

    • Impact population demographics and composition.

Women's Role in Society

  • As societies develop economically, women have more opportunities, leading to delayed marriage and childbirth, thus reducing TFR.

  • Gender equality indicators (GII, HDI) highlight disparities and inequalities in less economically developed societies, where women have fewer opportunities.

  • Women's participation in the formal economy increases with societal advancements.

Migration Concepts

  • Key Ideas:

    • Most migrants travel short distances.

    • Migrants traveling larger distances generally go to urban areas.

    • Every migration stream creates a counter-stream.

    • Economic factors/opportunities play a significant role.

  • Gravity Model: Larger cities have greater pull factors due to more opportunities.

  • Push and Pull Factors: Factors that induce people to leave (push) or attract them to a new location (pull).

  • Intervening Obstacles and Opportunities:

    • Intervening Obstacle: A negative factor that stops or hinders migration (e.g., immigration quotas, lack of funds).

    • Intervening Opportunity: A positive factor that stops migration (e.g., job opportunity in transit).

  • Types of Migration:

    • Internal migration (Intra-regional/Inter-regional).

    • International migration.

    • Voluntary migration.

    • Forced migration: (Human trafficking..etc)

      • Refugees: Forced to cross an international boundary.

      • Asylum seekers.

      • Internally Displaced Persons (IDPs): Flee their homes but remain within the state.

  • Transnational Migration: Maintaining connections with the country of origin. Often migrate to locations with similar cultural characteristics.

  • Transhumance: Cyclical/Seasonal migration with livestock.