Unit 2: Population and Migration Review Notes

Population Distribution and Density

• Population Distribution: How people are spread out across a given area.

  • Influenced by: climate, landforms (mountains, plains, plateaus), water bodies (rivers, lakes, oceans), culture, economics, history (wars, colonization), and politics (government policies). Site (absolute location, physical characteristics - soil type, climate) and situation (relative location, connections - transportation routes, proximity to resources) impact settlement locations, influencing population distribution.

• Population Density: The number of people living in a specific area.

  • Three main types:

  • Arithmetic Density: Total population divided by total land area. This is the basic population density, but it doesn't account for variations in land use or habitability.

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

  • Physiological Density: Total population divided by arable land (farmable land). Indicates stress on the environment and the ability of the land to support the population.

    Physiological Density = \frac{Total Population}{Arable Land}

    • Low physiological density: less stress on the environment, easier to produce food, less reliance on imports. Example: United States, Canada.

    • High physiological density: more stress on the environment, requires more resources to feed the population. Example: Egypt, Bangladesh.

  • Agricultural Density: Number of farmers divided by arable land. Shows how advanced agricultural practices are. It can indicate the efficiency of agricultural production.

    Agricultural Density = \frac{Number of Farmers}{Arable Land}

    • Low agricultural density: more efficient, using more technology (tractors, combines, GPS), allowing people to do other jobs. Typical in more economically developed countries.

    • High agricultural density: less efficient, using less technology, more farmers needed, often seen in less economically developed countries. Example: Subsaharan Africa.

    • Connection to economic development: As countries develop, agricultural density decreases, and more people move to secondary, tertiary, quaternary, and quinary sectors.

Carrying Capacity

• Definition: The maximum number of individuals that the environment can sustain given available resources and technology. Exceeding carrying capacity can lead to environmental degradation and resource depletion.

• Consequences of Population Distribution and Density:

  • Impacts political factors (laws, taxes, representation in government), Example: Gerrymandering

  • Economic factors (job availability, income levels, cost of living).

  • Social pressures (access to education, healthcare, social services).

  • Opportunities vary based on density and distribution.

  • Densely populated urban areas: more services (healthcare, education, retail), healthcare, public transportation, job opportunities, cultural amenities.

  • Dispersed rural areas: more green spaces, less traffic, lower cost of living, stronger sense of community.

Sex Ratio

• Definition: The number of males per 100 females in a population.

• Under 100: fewer males than females, common in older populations due to longer female lifespans.

• Over 100: more males than females, can be influenced by cultural preferences, sex-selective abortions, or migration patterns.

• 100: equal number of males and females.

• Changes over time: As societies age, sex ratios can become imbalanced because men tend to participate in riskier behavior (e.g., war, dangerous occupations) and have shorter lifespans than women, or due to government policies that favor one gender over another.

Dependency Ratio

• Definition: Measures the proportion of dependents (children and elderly) to the working-age population (15-64 years old). A high dependency ratio can strain resources and affect economic growth.

• Components:

  • Child Dependency Ratio: Focuses on people too young to work (0-14 years).

  • Elderly (Age) Dependency Ratio: Focuses on people who are retired (65+ years).

• Significance:

  • High elderly dependency ratio: working population has a higher tax burden, potential job shortages, and social/cultural shifts (e.g., families taking in elderly relatives). Example: Japan, Italy.

  • High child dependency ratio: need for more preschools and daycare, challenges in supporting the working population with children. Example: Nigeria, Uganda.

Aging Societies

• Characteristics: declining birth rates, increasing elderly population, longer life expectancies, lower fertility rates

• Consequences:

  • Decreasing population. potential labor shortages, slower economic growth.

  • Increased need for elderly care facilities (nursing homes, assisted living).

  • Shift in government funding priorities (healthcare, pensions).

  • Changes in voting patterns (more focus on elderly issues).

  • Increased medical costs.

  • Potential implementation of pronatalist policies (incentives for having children).

Population Pyramids

• Definition: Graphic representation of a population's age and sex composition. It provides insights into a population's demographic structure and future trends.

• Components:

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

  • Pre-reproductive years (0-14).

  • Reproductive years (15-44).

  • Post-reproductive years (45+).

• Insights Gained:

  • Stage of demographic transition (expanding, stable, declining).

  • Elderly and child dependency ratios.

  • Sex ratios. imbalances can indicate gender-selective practices or migration patterns.

• Analysis: Population pyramids are snapshots in time; future populations dynamically shift due to changes in birth rates, death rates, and migration patterns.

Population Dynamics

• Key Terms:

  • Crude Birth Rate (CBR): Total number of births per 1,000 people in a year. Influenced by factors like access to healthcare, education, and cultural norms.

  • Crude Death Rate (CDR): Total number of deaths per 1,000 people in a year. Affected by factors like healthcare quality, sanitation, and nutrition.

  • Rate of Natural Increase (RNI): CBR minus CDR (migration not factored in). It indicates the percentage at which a population is growing or declining annually.

  • Total Fertility Rate (TFR): Average number of children a woman will have in her lifetime. It's a key indicator of future population growth.

  • Infant Mortality Rate (IMR): Number of deaths of infants under one year old per 1,000 live births. Reflects the quality of healthcare systems and living conditions.

  • Doubling Time: Time it takes for a population to double in size, assuming a constant rate of natural increase. It's calculated using the rule of 70: Doubling Time = 70 / RNI.

Demographic Transition Model (DTM)

• Definition: A model that describes population change over time, based on economic development. It illustrates how birth rates and death rates change as a country develops.

• Stages:

  • Stage 1: High birth and death rates, low total population, primary sector jobs (agriculture, hunting). Population growth is slow and fluctuating.

  • Stage 2: Death rates fall due to industrial and medical revolutions (improved sanitation, nutrition, and healthcare), birth rates remain high, population increases rapidly. Example: Many countries in Subsaharan Africa.

  • Stage 3: Birth rates begin to fall as cultural and economic changes occur (increased education for women, urbanization), population growth slows. Example: Brazil, Mexico.

  • Stage 4: Low birth and death rates, population stabilizes, countries may implement pronatalist policies, international migration increases. Example: United States, Japan.

  • Stage 5: Birth rates fall below death rates, population declines, aging population, potential labor shortages. Example: Germany, Italy

• Zero Population Growth (ZPG): Births equal deaths, resulting in no population growth.

Epidemiologic Transition Model

• Definition: Focuses on causes of death in each stage of the demographic transition model. It explains the shift in disease patterns as a country develops.

• Stages:

  • Stage 1: Deaths due to animal attacks, famine, and parasitic diseases. High death rates due to infectious diseases and lack of healthcare.

  • Stage 2: Receding pandemics due to improved sanitation and nutrition. Death rates decline as sanitation and access to healthcare improve.

  • Stage 3: Degenerative diseases (cancer, heart disease) become more prominent. Lifestyle-related diseases become the primary causes of death.

  • Stage 4: Efforts to delay degenerative diseases through healthier lifestyles and advanced medical care. Medical advancements extend life expectancy and delay the onset of age-related illnesses.

  • Stage 5: Reemergence of infectious diseases due to disease evolution (antibiotic resistance), increased poverty and urbanization, and globalization (rapid spread of diseases). Example: COVID-19, Tuberculosis

Malthusian Theory

• Thomas Malthus: Population grows exponentially while food production grows arithmetically, leading to a Malthusian catastrophe (resource scarcity, war, famine). He argued that population growth would inevitably outstrip food supply, leading to widespread starvation and social unrest.

• Neo-Malthusians: View that Earth's resources can only support a finite population and advocate for policies to curb population growth. They emphasize the importance of sustainable resource management and family planning.

• Critiques: Malthus did not account for:

  • advancements in agricultural technology (Green Revolution, genetic modification).

  • demographic transition model (decline in birth rates as countries develop).

Government Policies

• Pronatalist Policies: Incentives to increase birth rates (tax breaks, childcare support, propaganda). Example: France, Russia.

• Antinatalist Policies: Measures to reduce birth rates (China's one-child policy, India's sterilization programs). Often involve promoting family planning and access to contraception.

• Immigration Policies: Quotas limit the number of immigrants allowed into a country. Governments regulate immigration through visas, border controls, and asylum processes.

• Impact: Governments can influence population demographics and growth rates through these policies. Policies can have long-term consequences on a country's economy, society, and culture.

Women's Role in Society

• As societies develop economically, women gain more opportunities, delaying marriage and childbirth. Increased access to education and employment leads to smaller family sizes.

• Increased participation in the formal economy. Women's economic empowerment contributes to lower fertility rates.

• Societies with greater gender equality tend to have lower total fertility rates. Gender equality is associated with better healthcare, education, and economic opportunities for women.

Ravenstein's Laws of Migration

• Economics: primary motivator for migration. People migrate for better job opportunities and higher wages.

• Short distances: most migrants travel a short distance. Distance decay: the farther away a place is, the less likely people are to migrate there.

• Urban areas: migrants who travel larger distances are going to urban areas. Cities offer more diverse job opportunities and amenities.

• Families: are less likely to migrate across borders. Family ties and cultural attachments can deter long-distance migration.

• Counterstream: every migration stream creates a counterstream. Return migration: migrants return to their home country due to various reasons.

• Step migration: migrants travel in a series of steps. People gradually move from rural areas to small towns, then to larger cities.

• Shifts: Some laws have shifted, like women are able to travel farther distances now because they have more access to capital/money. Increased gender equality has changed migration patterns.

Gravity Model

• Larger cities attract more migrants due to more opportunities (jobs, social factors). The size of a city is directly proportional to its attractiveness to migrants.

• Larger the city, the larger the job growth, and it's more socially easier to go there because more people are there. Social networks and communities provide support for migrants.

Push and Pull Factors

• Pull Factors: Positive conditions that attract people to an area (job opportunities, better healthcare, political stability). Examples: Economic opportunities in a new city, better educational facilities.

• Push Factors: Negative conditions that cause people to leave an area (poverty, violence, environmental disasters). Examples: War, famine, natural disasters.

Migration Terminology

• Emigration: Leaving a country (E for Exit). Example: A person leaving Mexico to live in the United States.

• Immigration: Entering a country (I for In). Example: A person from Mexico entering the United States to live.

• Intervening Obstacles: Negative situations that hinder migration (e.g., immigration quotas, lack of funds, restrictive immigration laws). Examples: Border walls, visa requirements.

• Intervening Opportunities: Positive situations that stop migration (e.g., job opportunities). A migrant finds a good job along the way and decides to stay there.

• Inter-regional Migration: Movement from one region to another within a country. Example: Moving from the East Coast to the West Coast of the United States.

• Intra-regional Migration: Movement within one region. Example: Moving from a city to a suburb within the same metropolitan area.

Forced vs. Voluntary Migration

• Forced Migration: Includes human trafficking, forced labor, and displacement due to conflict or disasters. People are compelled to move against their will due to external factors.

  • Refugees: forced person to cross an international boundary due to persecution, war, or disaster. They seek protection in another country.

  • Asylum Seekers: Those seeking protection/access into a country. They apply for refugee status upon arrival.

  • Internally Displaced Persons (IDPs): Flee their homes but remain within their country. They have not crossed an international border.

• Voluntary Migration: Types include:

  • Transnational Migration: Immigrants maintain connections to their home country. They send remittances, visit family, and participate in political activities.

  • Transhumance: Cyclical migration patterns that occur with livestock. Herders move their animals seasonally to find grazing lands.

  • Chain Migration: Legal immigrants sponsor family members to immigrate. It creates migration chains based on family and community ties.

  • Step Migration: Migration occurring in stages. People gradually move from smaller to larger places.

  • Guest Workers: Individuals with temporary legal status working in a country. They fill labor shortages in specific sectors.

  • Rural-to-Urban Migration: Movement from rural areas to urban centers seeking economic opportunities. It's a major driver of urbanization.

Effects of Migration

• Cultural resistance. Migration leads to cultural exchange and the blending of traditions.

• Increased economic opportunities. Migrants contribute to the economy through labor and innovation.

• Diffusion. Migration facilitates the spread of ideas, technologies, and cultural practices.

• New business openings. Immigrants often start businesses and create jobs.

• Social opportunities. Migration can lead to greater social diversity and inclusion.