Unit 2

Population Distribution: The pattern of where people live in an area.
Population Density: The number of people per unit area of land.
- Arithmetic Density: Total number of people divided by total land area. $\text{Arithmetic Density} = \frac{\text{Total Population}}{\text{Total Land Area}}$
- Physiological Density: Total number of people divided by the area of arable (farmable) land. $\text{Physiological Density} = \frac{\text{Total Population}}{\text{Arable Land Area}}$
- Agricultural Density: The number of farmers divided by the area of arable land. $\text{Agricultural Density} = \frac{\text{Number of Farmers}}{\text{Arable Land Area}}$

Crude Birth Rate (CBR): The total number of live births per 1,000 population in a year. $\text{CBR} = \frac{\text{Live Births}}{\text{Total Population}} \times 1000$
Crude Death Rate (CDR): The total number of deaths per 1,000 population in a year. $\text{CDR} = \frac{\text{Deaths}}{\text{Total Population}} \times 1000$
Natural Increase Rate (NIR): The percentage by which a population grows in a year ( $\text{CBR} - \text{CDR}$ per 1,000, then divided by 10 to get percentage). $\text{NIR} = \frac{\text{CBR} - \text{CDR}}{10}$
Total Fertility Rate (TFR): The average number of children a woman will have during her childbearing years.
Infant Mortality Rate (IMR): The annual number of deaths of infants under one year of age, compared with total live births. $\text{IMR} = \frac{\text{Infant Deaths}}{\text{Live Births}} \times 1000$
Life Expectancy: The average number of years an individual can be expected to live.
Doubling Time: The number of years needed to double a population, assuming a constant rate of natural increase. Often calculated as $\frac{70}{\text{NIR (as percentage)}}$ .

Population Composition: The structure of a population in terms of age, gender, and other characteristics.
Population Pyramid: A bar graph that displays the percentage of a place's population for each age group and by gender.
- Expansive Pyramids: Wide at the base, indicating high birth rates and rapid population growth (LDCs).
- Constrictive Pyramids: Narrow at the base, indicating low birth rates and an aging population (MDCs).
- Stationary Pyramids: Somewhat rectangular, indicating stable birth rates and slow-to-no population growth.

Thomas Malthus's Theory: Argued that population growth is exponential, while food supply increases arithmetically, leading to resource scarcity and crises.
- Malthusian Catastrophe: A predicted point where population overwhelms food supply.
Neo-Malthusians: Supporters who have adapted Malthus's ideas to include other resources (water, energy) and advocate for sustainable population policies.
Critics of Malthus: Argue that technology, innovation, and social changes (e.g., changes in women's roles) allow food supply to keep pace with or exceed population growth.

A model showing the historical population changes of birth and death rates in countries.

Stage 1: Low Growth
- High CBR, High CDR, very low NIR.
- Pre-industrial societies, hunter-gatherer era.
Stage 2: High Growth
- High CBR, rapidly declining CDR, very high NIR.
- Industrialization, improved sanitation and medicine (e.g., Gambia, Yemen).
Stage 3: Moderate Growth
- Rapidly declining CBR, moderately declining CDR, moderate NIR.
- Women's empowerment, urbanization, declining family size (e.g., Mexico, India).
Stage 4: Low Growth
- Low CBR, Low CDR, very low or zero NIR.
- Post-industrial, developed countries (e.g., USA, UK, China).
Stage 5: Declining (or Negative) Growth (proposed)
- CDR exceeds CBR, resulting in negative NIR (e.g., Japan, Germany).

Focuses on distinctive causes of death in each stage of the DTM.

Stage 1 (Pestilence and Famine): Infectious and parasitic diseases are primary causes of death; high death rates.
Stage 2 (Receding Pandemics): Decreasing death rates due to improved sanitation, nutrition, and medicine.
Stage 3 (Degenerative and Human-Created Diseases): Decrease in deaths from infectious diseases, increase in chronic disorders associated with aging (e.g., heart attack, cancer).
Stage 4 (Delayed Degenerative Diseases): Life expectancy extended through medical advances, but same chronic maladies persist.
Stage 5 (Reemergence of Infectious and Parasitic Diseases) (proposed): Evolution of microbes, poverty, and increased travel lead to new/resurgent infectious diseases.

Pronatalist Policies: Government policies that encourage births (e.g., tax incentives for larger families, parental leave).
Antinatalist Policies: Government policies that discourage births (e.g., China's former One-Child Policy, family planning education, access to contraception).

Migration: A permanent or semi-permanent change of residence.
Emigration: Migration from a location.
Immigration: Migration to a location.
Net Migration: The difference between the number of immigrants and the number of emigrants.
Mobility: All types of movement from one location to another.
Circulation: Short-term, repetitive, or cyclical movements that recur on a regular basis.

Internal Migration: Movement within a country.
- Interregional Migration: Movement from one region to another within a country (e.g., rural to urban).
- Intraregional Migration: Movement within one region (e.g., within urban areas from older cities to newer suburbs).
International Migration: Movement across country borders.
- Voluntary Migration: Migrant chooses to move, usually for economic reasons or personal preference.
- Forced Migration: Migrant is compelled to move (e.g., refugees, internally displaced persons, asylum seekers).
- Refugee: Someone forced to migrate from their home country and cannot return for fear of persecution.
- Internally Displaced Person (IDP): Someone forced to migrate within their own country.
- Asylum Seeker: Someone who has migrated to another country in hope of being recognized as a refugee.

Push Factors: Induce people to move out of their present location.
- Economic: lack of jobs, poverty.
- Social: discrimination, lack of social services.
- Political: persecution, armed conflict, instability.
- Environmental: natural disasters, climate change, lack of resources.
Pull Factors: Induce people to move into a new location.
- Economic: job opportunities, higher wages.
- Social: family reunification, better quality of life, education.
- Political: political freedom and stability.
- Environmental: attractive landscapes, favorable climate.
Intervening Obstacles: Environmental or cultural features that hinder migration (e.g., oceans, mountains, lack of money, immigration laws).
Intervening Opportunities: Opportunities closer to home that deter migrants from traveling further away.

Distance Decay: Most migrants move short distances and remain within their own country.
Step Migration: Migration occurs in a series of shorter steps rather than one long movement.
Rural-Urban Migration: Main flow of migration is from rural to urban areas.
Counter-Migration: Every migration flow creates a return or counter-flow.
Demographics of Migrants: Most