Unit 2: Population and Migration Patterns and Processes

Unit 2 Big Ideas

I. How does where and how people live affect global cultural, political, and economic patterns?
II. How do the interplay of environmental, economic, cultural, and political factors change the population?
III. How do changes in population affect a place’s economy, culture, and politics?

2.1 Population Distribution

Essential Knowledge:
- PSO 2A1: Physical factors (e.g., climate, landforms, water bodies) and human factors (e.g., culture, economics, history, politics) influence the distribution of population.
- PSO 2A2: Factors that illustrate patterns of population distribution vary according to the scale of analysis.
- PSO 2B1: The three methods for calculating population density are arithmetic, physiological, and agricultural.
- PSO 2C1: The method used to calculate population density reveals different information about the pressure the population exerts on the land.
Learning Objectives:
- Identify the factors that influence the distribution of human populations at different scales.
- Define methods geographers use to calculate population density.
- Explain the differences between and the impact of methods used to calculate population density.

I. Factors in Population Distribution

Physical factors influence population distribution.
- Basic needs:
  - Humans need food, water, and shelter to survive.
  - Populations develop in proximity to these resources.
- Most people live in:
  - Midlatitudes ( $30N$ to $60N$ + $30S$ to $60S$ )
  - Low-lying areas
  - Near sources of freshwater
  - Near other valuable resources like minerals, metals, and timber
Ecumene:
- Refers to the part of the Earth’s surface occupied by permanent human settlement.
- Illustrates the effect of physical features on the location of human settlement.
Sparsely populated regions include:
- Dry lands (about 20% of Earth’s land)
- Wetlands (rain + heat rapidly deplete nutrients)
- Cold lands (hard on crops, too cold for living)
- Highlands (steep and often snow-covered)
Human factors influence population distribution.
- Preference for some natural features
- People like to live near friends/relatives and places that they perceive as safe
- Near similar cultural groups
- Near transportation/trade networks
- Near economic opportunities

II. Population Distribution at Various Scales

Patterns in population distribution can be identified at different scales:
- Global scale
- Regional scale
- National scale
- Local scale

III. Calculating Population Density

Three methods to calculate population density:
- Arithmetic
- Physiological
- Agricultural

Arithmetic Density

Calculated by dividing a region’s population by its TOTAL LAND AREA.
- Example: United States
  - Approx. $345,426,571$ people
  - $3,809,525$ square miles
  - Arithmetic Density = $91$ people/square mile
Does not tell us about population distribution.
- Where do you think has more than $91$ people in a square mile?
- Where do you think has a lot less than $91$ people in a square mile?

Physiological Density

Calculated by dividing a region’s population by its amount of ARABLE LAND.
- Example: Egypt
  - Approx. $116,791,664$ people
  - Total land area = $387,050$ miles\textsuperscript{2}
  - Arable land = $10,837$ miles\textsuperscript{2} (3%)
  - Arithmetic Density = $302$ people per mile\textsuperscript{2}
  - Physiological Density = $10,777$ people/mile\textsuperscript{2} of arable land
Allows to see:
- A population’s strain on the land/available resources
- A region’s carrying capacity and whether that region can be considered overpopulated
  - Carrying capacity: the number of people an area can support without damaging the environment
  - Overpopulation: the number of people have exceeded an area’s carrying capacity
    - Knowing an area’s carrying capacity and current population is required to identify overpopulated areas

Agricultural Density

Calculated by dividing a region’s population of farmers by its amount of ARABLE LAND.
- Example: Netherlands
  - Total Population = $18,245,187$
  - Total Land Area = $16,160$ mi\textsuperscript{2}
  - Total Arable Land = $4,814$ mi\textsuperscript{2} (30%)
  - Total of farmers = $349,286$ (1.9%)
    - Arithmetic: $1,129$ /mi\textsuperscript{2}
    - Physiological: $3,790$ /mi\textsuperscript{2} of arable land
    - Agricultural: $73$ farmers/mi\textsuperscript{2} of arable land
- Example: Bangladesh
  - Total Population = $173,863,205$
  - Total Land Area = $57,321$ mi\textsuperscript{2}
  - Total Arable Land = $35,713$ mi\textsuperscript{2} (62%)
  - Total of farmers = $69,545,282$ (40%)
    - Arithmetic: $3,033$ /mi\textsuperscript{2}
    - Physiological: $4,868$ /mi\textsuperscript{2} of arable land
    - Agricultural: $1,947$ /mi\textsuperscript{2} of arable land
Regions with a LOW agricultural density are likely to be MORE DEVELOPED.
- Farmers in more developed regions have access to advanced agricultural technology that allows for work to be completed by fewer people.
Regions with a HIGH agricultural density are likely to be LESS DEVELOPED.
- Farmers in less developed regions have little to no access to agricultural technology. Therefore, more human labor is required.

IV. The Impact of Population Densities

If PHYSIOLOGICAL DENSITY is…
- HIGH:
  - There isn’t a high percentage of arable land.
  - Where are we getting our food?
  - Can we grow enough food to support our population?
  - Will we need to buy food from another region?
- LOW:
  - There is plenty of arable land.
  - What will we do with our agricultural surplus?
  - Will we sell it?
If AGRICULTURAL DENSITY is…
- LOW:
  - We need fewer people to participate in farming/agriculture.
  - What other jobs might support our population?
- HIGH:
  - We need more people to participate in farming/agriculture.
  - Will we fall behind in technology/advancements because so many of our people need to help grow our food supply?

2.1 Check for Understanding

List the human and physical factors that influence population distribution.
List and describe the 3 methods of calculating population density.
What can we infer about a country that has a low arithmetic density, a high agricultural density, and a high physiological density?

2.2 Consequences of Population Distribution

Essential Knowledge:
- PSO 2D1: Population distribution and density affect political, economic, and social processes, including the provision of services such as medical care.
- PSO 2D2: Population distribution and density affect the environment and natural resources; this is known as carrying capacity.
Learning Objectives:
- Explain how population distribution and density affect society and the environment.

I. Impact of Population Distribution

Social
- The social services provided are based on the needs of the population.
  - A large population provides:
    - Social services include public schools, police stations, fire stations, social program offices, etc.
    - A more densely populated city will have more public schools, first responders, etc.
    - Rural areas have less access to these services/services are more spread out
Political
- Electoral Districts (Voting Districts) are based on population sizes.
  - Districts can be redrawn every 10 years based on collected census data
  - As urban populations grow, districts need to be redrawn to include equal populations
    - The voting districts in Metro-Atlanta are much smaller in area than voting districts in more rural regions of Georgia
Economic
- The economy is directly impacted by the size of the local population.
  - A large population provides:
    - More labor for the workforce
    - More people to act as consumers - boosts the economy
    - Industries and businesses choose to locate near more densely populated areas
Environmental
- Larger populations cause a greater strain on the environment
  - Overpopulation means a population has exceeded the carrying capacity of the space
- Environmental strain can lead to:
  - Air and water pollution
  - Depletion of vital resources like fresh water
  - Loss of valuable agricultural land

2.2 Check for Understanding

Describe a political impact of population distribution.
Describe an economic impact of population distribution.
Describe a social impact of population distribution.
Describe an environmental impact of population distribution.

2.3 Population Composition

Essential Knowledge:
- PSO 2E1: Patterns of age structure and sex ratio vary across different regions and may be mapped and analyzed at different scales.
- PSO 2F1: Population pyramids are used to assess population growth and decline and to predict markets for goods and services.
Learning Objectives:
- Describe elements of population composition used by geographers.
- Explain ways that geographers depict and analyze population composition.

I. Population Composition

Ethnicity
- Ethnic groups are often clustered in specific areas due to:
  - Immigrants forming ethnic enclaves
  - Discrimination of minority ethnic groups
  - Historic patterns of forced migration and persecution
Age and Sex
- Age composition can vary across regions and different scales of analysis
  - Average age in the state of Utah - 29-30
  - Average age in the state of Maine - 43-44
  - Younger populations tend to cluster in urban areas
- Sex/gender composition can vary due to:
  - Wars
  - Location of military bases and colleges/universities
  - Government policies and cultural norms

II. Population Pyramids

Population pyramids are age-sex composition graphs
- They’re based on percentages of males and females within different age groups in a specific area
- Can be created at various scales - cities, states, regions, countries, etc.
- Population pyramids provide a visual representation of birth rates, death rates, life expectancy, and economic development
  - HOWEVER - these EXACT statistics cannot be extrapolated from a population pyramid
- Population pyramids can show evidence of:
  - Natural disasters
  - Wars
  - Political changes/policies
  - Epidemics
Reading a population pyramid
- Vertical axis shows different age groups (cohorts in 5-year intervals - 0-4, 5-9, 10-14, etc.)
- Horizontal axis provides absolute numbers or percentages of males and females in each age cohort
  - Males are usually to the left of the vertical axis
  - Females are usually to the right of the vertical axis
Population Trends I
- A wide base that tapers upward shows a high crude birth rate
- As children in the younger cohorts age, they will likely have children and continue the trend of population growth.
Population Trends II
- A narrow base that expands upward shows a low crude birth rate and high life expectancy
- If this trend continues, the region may experience a decline in total population and consequences of an aging population.
Impact of War
- Majority of lives lost are generally males from ages 18-40
- Couples delay having children until after war/times of peace and stability
- This can lead to a birth deficit - sudden drop in births
Boom, Busts, + Echos
- Boom - sudden increase in births
  - Occurs during times of peace and stability
  - WWII Baby Boom - 1946-65
- Bust - drop in birth rates after a boom
- Echo - a reflection of the boom
  - Boom babies reach child-rearing age
Anomalies
- Populations are typically relatively symmetrical, with a similar distribution of males and females in each age cohort
- An anomaly is something that deviates from what is expected.
  - Bars are longer for people ages 18 to 25 than for people younger or older.
    - A small city includes a large university.
    - A shortage of school funding causes families to move away when they have children.
  - Bars are longer for people ages 25 to 50 than for children.
    - An economic crisis causes people to decide to have fewer children.
    - A government policy to slow population growth discourages births.
    - An epidemic causes many infants to die.
  - Bars are longer for people over the age of 65.
    - A community in a warm climate attracts retirees.
    - A lack of jobs causes young people to move away.
  - Bars are longer for males than females.
    - An oil boom attracts people for jobs that are traditionally done by men.
Dependency Ratio
- Comparison of potential workforce to the “dependent population”
  - Potential workforce - ages 15-64
  - Dependent population
    - Youth - 0-14
    - Elderly - 65+
- Dependency Ratio = dependent population/ potential workforce
  - $Dependency Ratio = \frac{dependent\ population}{potential\ workforce}$
  - Example:
    - United States
      - 0-14: 18.1%
      - 15 to 64: 63.4%
      - 65+: 18.5%
      - $Dependency\ Ratio = \frac{18.1 + 18.5}{63.4} = 0.57$
    - Niger
      - 0-14: 49.5%
      - 15 to 64: 47.8%
      - 65+: 2.7%
      - $Dependency\ Ratio = \frac{49.5 + 2.7}{47.8} = 1.09$

2.3 Check for Understanding

Which population statistics are used to create a population pyramid?
Describe the shape of a population pyramid in a country with rapid population growth.
Describe the shape of a population pyramid in a country with slow population growth or declining population?
How do you calculate the dependency ratio? How do you calculate the youth or elderly dependency ratio?

2.4 Population Dynamics

Essential Knowledge:
- IMP 2A1: Demographic factors that determine a population’s growth and decline are fertility, mortality, and migration.
- IMP 2A2: Geographers use the rate of natural increase and population-doubling time to explain population growth and decline.
- IMP 2A3: Social, cultural, political, and economic factors influence fertility, mortality, and migration rates.
Learning Objectives:
- Explain factors that account for contemporary and historical trends in population growth and decline.

I. Demographic Factors

Mortality - a measure of the number of deaths in a particular population per unit of time.
- Crude Death Rate (CDR) - total number of deaths per 1000 people over the age of 1
- Infant Mortality (IMR) - total number of infant deaths per 1000 live births
- Maternal Mortality (MMR) - total number of maternal deaths due to pregnancy or childbirth per 1000 successful pregnancies/births
- Life Expectancy - the average number of years a person is predicted to live
- Each of these factors are indications of a country’s development. A more developed country should have lower CDR, IMR, and MMR, and a higher life expectancy due to access to quality healthcare.
Fertility - measures the likelihood of population growth through childbirth
- Total Fertility Rate (TFR) - the average number of children a woman is likely to have within her lifetime
- Crude Birth Rate (CBR) - the total number of births per 1000 people
- Rate of Natural Increase (RNI) - the percentage of population increase over 1 year
Migration
- Immigration - IN migration
- Emigration - OUT migration
- Demographic Balancing Equation
  - Find the NET migration by subtracting the emmigration from immigration.
  - Demographic Balancing Equation = Current population + (CBR-CDR) + (# of Immigrants - # of Emmigrants)

II. Population Growth + Decline

Rate of Natural Increase
- Calculating RNI
  - Based on CBR and CDR
  - RNI = (CBR - CDR)/10 = __%
  - This does not include changes to population size due to migration
  - Find the RNI of the United States
    - CBR: 12.2
    - CDR: 8.5
    - (12.2-8.5)/10 = 0.37%
- Global RNI ~1.2%
  - Based on this RNI, what will the world population be in 1 year?
  - Current global population: 8,172,242,415
  - Total Pop (RNI) = ____ + Total Pop = Pop in 1 year
  - Pop in 1 year = 8,270,309,324
Doubling Time
- Doubling Time refers to the number of years it will take for a population to double if the RNI remains constant.
- To estimate doubling time, use the rule of 70 or 72.
  - Approx. doubling time in years = 70/RNI
  - Example: Ivory Coast = 70/2.5(RNI) = 28 years
  - Example: United States = 70/0.37(RNI) = 189 years
Trends in Population Growth + Decline
- Largest population growth in less developed/developing regions
  - Sub-Saharan Africa
- Population decline is happening in the most developed countries.
  - Japan has a growth rate of -0.5
  - Some countries in Europe are also trending towards a negative RNI
    - Italy: -0.41
    - Spain: -0.29
    - Germany: -0.31

III. Factors that Influence Demographic Change

Population Growth + Decline are influenced by:
- Economic Development - greater economic development means access to resources like healthcare, higher education, and employment opportunities
- Education - there is a direct relationship between access to education and a region’s TFR
- Gender Empowerment - regions with greater gender equality have a lower TFR as women are empowered to pursue education and opportunities outside of the home
- Healthcare - quality health care will lead to a decrease in IMR and MMR as well as fewer unplanned pregnancies
- Cultural Traditions - some cultural traditions value larger families
- Public Policy - pronatalist and anti-natalist policies can lead to a rise or fall in RNI

2.4 Check for Understanding

List and describe the demographic factors that measure a region’s mortality.
List and describe the demographic factors that measure a region’s fertility.
Explain the relationship between RNI and Doubling Time.
Describe 3 factors that influence demographic change.

2.5 The Demographic Transition Model

Essential Knowledge:
- IMP 2B1: The demographic transition model can be used to explain population change over time.
- IMP 2B2: The epidemiological transition explains causes of changing death rates.
Learning Objectives:
- Explain theories of population growth and decline.

I. The Demographic Transition Model (DTM)

“Demographic Transition” refers to changes within a region’s population in response to modernization over time.
- The DTM provides a visual representation of each stage of the DTM.
- A region/country’s stage is dependent on its CBR, CDR, and RNI.
DTM Stages:
- Stage 1: High CBR, High CDR, Zero/No Growth, None/Isolated Groups
- Stage 2: Rapidly Falling CDR, High CBR, Rapid Growth, Afghanistan/Yemen
- Stage 3: Slowly Falling CDR, Falling CBR, Rapid Growth, India, Mexico, South Africa
- Stage 4: Low CDR, Low CBR, Zero/No Growth, USA, Canada, Brazil
- Stage 5: Below CDR, Low CBR, Negative Growth, Japan, Germany
Stage 1 Population Pyramid - Niger
- Very few people living to older age cohorts = low life expectancy/high CDR
- Sharp decrease in population as you move into older cohorts = rapid population growth/lack of health care, high number of “preventable deaths”
- Wide base = high CBR
Stage 2 Population Pyramid - Afghanistan
- More people living to older age cohorts = increasing life expectancy/decreasing CDR
- Gradual decrease in population as you move into older cohorts = rapid population growth/lack of health care, high number of “preventable deaths”
- Wide base = high CBR
Stage 3 Population Pyramid - India
- More people living to older age cohorts = increasing life expectancy/decreasing CDR
- Very little decrease in population as you move into older cohorts = access to health care increases life expectancy
- Tapering base = decreasing CBR
Stage 4 Population Pyramid - USA
- Many people living to older age cohorts = increasing life expectancy/low CDR
- Population size is consistent as you move into older cohorts = access to health care increases life expectancy
- Decreasing base = decreasing CBR
Stage 5 Population Pyramid - Japan
- Many people living to older age cohorts = increasing life expectancy/low CDR
- Majority of population in middle-aged/older age cohorts = “aging population”
- Consistently decreasing base = CBR has fallen below the CDR

II. The Epidemiological Transition Model (ETM)

Epidemiology is the study of diseases and other factors related to health.
- The ETM is divided into 5 stages that correspond with the 5 stages of the DTM.
- Shows us the primary cause(s) of death at each stage of development.
ETM Stages:
- Stage 1: Pestilence + Famine, High CDR
- Stage 2: Receding Pandemics, Rapidly Falling CDR
- Stage 3: Degenerative Diseases, Slowly Falling CDR
- Stage 4: Delayed Degenerative Diseases, Low/Stable CDR
- Stage 5: Reemergence of Infectious/Parasitic Diseases, Low/Stable CDR
Stage 1: Pestilence + Famine
- CDR: HIGH
- Causes of death: Diseases and famine are leading causes of death in Stage 1 country. Quality health care is not yet available. Populations are dying of diseases we’re now able to prevent/contain.
  - Example: The Black Plague decreased Europe’s population by 50%. The Black Plague is now treatable and does not spread thanks to improved health care and medical knowledge.
Stage 2: Receding Pandemics
- CDR: Rapidly Declining
- Causes of death: Pandemics devastate cities thanks to rapid urbanization increasing population density in urban areas.
  - Example: Cholera severely impacted London in the 1850s and Haiti in 2009.
Stage 3: Degenerative Diseases
- CDR: Slowly Declining
- Causes of death: Cause of death is now related to age. Populations are now living long enough to experience diseases and conditions that are a result of the aging body.
  - Examples: Heart Disease, many Cancers
Stage 4: Delayed Degenerative Diseases
- CDR: Low/Stable
- Causes of death: Cause of death is now related to older age. Populations are now living long enough to experience diseases and conditions that are a result of the aging body and lifestyle choices.
  - Examples: Heart Diseases, Cancer, Alzheimer's, Stage 2 Diabetes
Stage 5: Reemergence of Infectious/Parasitic Diseases
- CDR: Low/Stable
- Causes of death: Diseases that have been contained using vaccines and antibiotics are mutating/evolving and reemerging due to resistance. Additionally, globalization leads to stronger connections between distant places and increases interaction between different groups of people.
  - Example: Tuberculosis cases are increasing in impoverished countries.

2.5 Check for Understanding

How do CBR and CDR change within each stage of the DTM?
List one group/country that falls within each stage of the DTM.
What are the primary causes of death at each stage of development (according to the ETM)?

2.6 Malthusian Theory

Essential Knowledge:
- IMP 2B3: Malthusian theory and its critiques are used to analyze population change and its consequences.
Learning Objectives:
- Explain theories of population growth and decline.

I. Malthusian Theory

Thomas Malthus - an English economist and demographer who lived from 1766 to 1834
- Developed a theory about the relationship between population growth and available food supplies.
Malthusian Theory
- Humans need food to survive.
- Food production increases arithmetically.
- Human population increases geometrically (exponentially)
- Malthus theorized that the population growth will outpace food supply and as a result, the environment will produce natural “checks” to population growth through famine.

III. Malthusian Theory - Criticisms

Malthus’ theory has been criticized for not considering Human Possibilism.
- Humans have developed technology to increase agricultural yield in order to meet the needs of the growing global population.
- Malthus also did not predict that families in more developed regions would choose to have fewer children.
Ester Boserup was a Danish economist who lived from 1910 to 1999.
- She proposed an alternative theory that more humans also means more hands to contribute to agriculture, not just more mouths to feed.

IV. Neo-Malthusians = “New” Malthusians

Neo-Malthusians adopted Malthus’ original theory but applied it to concerns regarding ALL necessary resources, not just food.
- Population growth will outpace our supply of food, fresh water, coal, petroleum, timber, etc.

2.6 Check for Understanding

Describe Malthusian Theory.
Why is Malthus’ Theory criticized? What did he not account for when developing his predictions?
What do Neo-Malthusians believe?

2.7 Population Policies

Essential Knowledge:
- SPS 2A1: Types of population policies include those that promote or discourage population growth, such as pronatalist, antinatalist, and immigration policies.
Learning Objectives:
- Explain the intent and effects of various population and immigration policies on population size and composition.

I. Population Policies

Governments may choose to implement population policies in order to control the growth/size of a population. Policies can include:
- Anti-natalist Policies
- Pronatalist Policies
- Immigration Policies

A. Anti-natalist Policies

Policies that are designed to discourage large family sizes in order to slow the rate of population growth. Anti-natalist policies can include rewards as well as consequences and might include:
- Increasing access to family planning services/resources
- Empowering women to pursue education and economic opportunities outside of the home
- Government-funded childcare, parental leave, or college tuition for families with fewer children
- Families with more children may be required to pay a fine or pay higher taxes
- Families with fewer children may receive a tax break
- Families who have more than the maximum number of children may face legal consequences
- Media/Propaganda that criticizes large families or praises small families.
- Examples:
  - India
    - India was considered a Stage 1 country until the 1940s due to their persistent rapid population growth.
    - Anti-natalist policies included:
      - Providing easy access to contraception (birth control)
      - Providing financial compensation to women in exchange for sterilization
      - Increasing access to education regarding women’s health.
    - Consequences of policies
      - CBR decreased, RNI decreased
      - Overall population did not decline but rate of population growth decreased
  - China
    - China’s “One Child” Policy
      - 1980 - 2016
      - Majority of families were limited to one child
      - Violations resulted in significant fines and social consequences
      - Some ethnic minorities were permitted to have up to 2 children.
    - Consequences of policies
      - CBR decreased, RNI decreased
      - Overall population did not decline but rate of population growth decreased
      - A cultural preference towards sons led to many daughters being abandoned or put up for adoption

B. Pronatalist policies

Policies that are designed to encourage large family sizes in order to increase the rate of population growth. Pronatalist policies can include rewards as well as consequences and might include:
- Decreasing access to family planning services/resources
- Pressuring women to forgo education or economic opportunities outside of the home
- Government-funded childcare, parental leave, or college tuition for families with more children
- Families with more children may be receive a monetary reward or tax break
- Families with fewer children may be required to pay higher taxes
- Media/Propaganda that criticizes small families or praises large families.
- Examples:
  - Singapore
    - Concern for “aging population” led to the implementation of pronatalist policies after 1987.
    - Pronatalist policies include:
      - Increased maternity leave
      - Media promoting large families
      - Limited access to family planning
      - Government-funded child care and education
      - Government-funded dating agencies
  - Post-War Germany + Soviet Union
    - Devastation to the male population led to pronatalist policies to rebuild populations.
    - Pronatalist policies included:
      - Media promoting large families
      - Limited access to family planning
      - Government-funded child care and education
      - Monetary rewards + medals for mothers of multiple children

C. Immigration Policies

Some countries encourage immigration, others discourage immigration.
- Policies that encourage immigration:
  - Guest worker programs
  - Family reunification policies
  - Pathways to residency
  - US’ Homestead Act of 1862
    - Claim a plot of land, work the land for 5 years to contribute to food supply, and you’ll be given ownership of your land.
- Countries may choose to encourage immigration because they:
  - want to diversify their population
  - need to increase their workforce in order to support the economy
  - want to attract talented and educated individuals from other countries
- Policies that discourage immigration:
  - Requiring a specific level of education
  - Restrictions on type of work that warrants a work visa
  - Quotas - a numerical limit on the number of immigrants per year
- Countries may choose to discourage immigration because they:
  - they want a culturally homogenous population
  - they are struggling to meet the needs of their current population
  - Xenophobia - the intense fear of persons from a different cultural group - can result in persecution, discrimination, or anti-immigrant policies

2.7 Check for Understanding

Define anti-natalist policy. What are some examples of anti-natalist policies?
Define pronatalist policy. What are some examples of pronatalist policies?
Define immigration policy. What are some examples of policies that encourage immigration? Discourage immigration?

2.8 Women and Demographic Changes

Essential Knowledge:
- SPS 2B1