Key Concepts:

Basic Population Statistics

• Population growth involves two main concepts: the rate of natural increase (RNI) and the demographic equation.

  • The demographic equation uses uses birth rates, death rates, immigration, and emigration statistics to show population growth

• Birth rate, also known as natality, is the crude birth rate (CBR) and an annual statistic

  • High birth rates: rural agricultural Third-World countries

  • Low birth rates:  urbanized industrial and service-based economies

  • Ex: total number of infants born living is counted for one calendar year and then calculated

    • CBR: Number of Live Births/Total Population x 1,000

• Death rate, also known as the mortality rate, is the crude death rate (CDR) and an annual statistic calculated in the same way as the birth rate.

  • High death rates: a country that is experiencing war, disease, or famine, such as poor Third-World countries experiencing poverty, poor nutrition, epidemic disease, and a lack of medical care.

  • Green Revolution: (increased food and nutrition) and access to sanitation, education, and health care

    • CDR: Number of Deaths/Total Population x 1,000

• The rate of natural increase (RNI), or the natural increase rate (NIR) is the annual percentage of population growth of that country for that one-year period.

  • RNI: Birth Rate - Death Rate/10%

• Negative RNI means the population has shrunk

  • Happens in in highly urbanized First-World countries and where the traditional roles of women in the country of mother and housewife have deteriorated significantly

• Reduced fecundity: when the majority of women are heavily engaged in business, they are far less likely to have children

  • Double-income no-kid (DINK) households and single-parent–single-child homes are far more common; higher rates of divorce

• Natural increase does not account for immigration or emigration

  • Ex: a country with a high rate of natural increase can have an unexpectedly low long-term population prediction if there is a large amount of emigration

• Doubling Time: how long it would take for a country to double in size

  • Formula: 70Rate of Natural Increase

• To estimate the RNI for each year in the future by examining a country’s position: (Pop. × RNI1) + (Pop. × RNI2) + (Pop. × RNI3) + (Pop. × RNIn) = Future Population

• Net Migration Rate (NMR): the number of immigrants minus the number of emigrants for every thousand members of the population; can be negative

  • Formula: Number of Immigrants - Number of Emigrants/Population /1,000

• Population Growth Percentage Rate = (Birth Rate - Death Rate) + Net Migration Rate/10%

• Total fertility rate (TFR) is the estimated average number of children born to each female of birthing age (15 to 45)

  • Formula: Number of Children Born/Women Aged 15 to 45

• Replacement rate is a TFR of 2.1

  • A large population must have 2.1 children per female of birthing age.

• Dependency ratio provides the number of people too young or too old to work compared to the number of people in the work force

MODELS

• The demographic transition model (DTM) is a theory of how population changes over time and provides insights into issues of migration, fertility, economic development, industrialization, urbanization, labor, politics, and the role of women.

  • Newly industrialized countries (NICs) can also be placed on the model, but you have to change the dates as to when they reach the significant turning points in their history

• The epidemiological transition model (ETM) specifically accounts for development due to the increasing population growth rates caused by medical advances

  • The phase of development is directly followed by a stabilization of population growth as the procreation rates decline

  • Can predict how its population will change over time and speculate as to how much it can grow in size

    • Ex: we can estimate a population projection that the planet’s population has reached only about two-thirds of its potential

• The S-Curve of Population

  • Ex: an animal population that receives a vast amount of food or removes predators from their habitat will result rapid population growth followed by a plateau or decline due to a population reaching or exceeding the area’s carrying capacity

Stage-By-Stage

• Stage One:

  • Historically characterized by pre-agricultural societies engaged in subsistence farming and transhumance

  • Birth rates and death rates fluctuate due to climate, warfare, disease, and ecological factors, but overall, both rates are high

  • Child mortality and infant mortality were very high

  • Result: little population growth until the later part of stage one when death rates begin to decline; RNI is generally low or negative

  • Present-day Third-World countries engaged in long periods of warfare have late stage one characteristics

• Stage Two:

  • Typically agriculturally based economies

  • Birth rates remain high and life expectancy rises while death rates decline over time; RNI increases

  • Infant and child mortality is still an issue due to a lack of medical care and

  • Poor nutrition for expectant mothers and infants

  • The vast majority of populations in stage two countries live in rural regions as a result of agriculture’s economic prominence

• Stage Two 1/2:

  • NIC countries are characterized by economies that focus on manufacturing as the primary form of economic production and employment

  • Birth and death rates decline

  • Rapid population growth; high RNIs; rapidly increasing rate of urbanization

    • Migrants responding to the pull factor of employment opportunity rapidly fill the cities

• Stage Three:

  • Historically where most “industrialized” or manufacturing-based countries were found in the transition

  • Shifted their economies to a more service-based focus

  • Birth and death rates decline due to urbanization

  • The diffusion of fertility control due to access to health care and the availability of contraceptives as well as reducing the diffusion of disease due to medical advances

• Stage Four and Five

  • Birth and death rates converge to result in limited population growth and population decline

  • Service industries like finance, insurance, real estate, health care, and communications that drive the economy; manufacturing is dying

  • Ex: in the United States, services are 80 percent of the gross domestic product (GDP) and manufacturing is only 20 percent

  • Both the final stages of the DTM and ETM occur when birth rates bottom out into the lower teens

  • Zero population growth (ZPG) (RNI of 0.0 percent): birth rates reach the same level as death rates

  • Elderly population means fewer people investing their money:

    • Causing less money to circulate through the society, which results in stagnation

    • Lower tax base to support the rest of the nation

    • Shortage of labor supply

• Countries that are near or below zero population growth levels offer incentives to citizens to have more children.

  • With so few children being born, fewer people enter the workforce over time

  • Become dependent upon foreign guest workers

• Many former Communist countries of Eastern Europe have stage four demographic characteristics

  • Economic restructuring has brought economic, political, and social hardship to many communities

• Malthusian Theory states that the global population would one day expand to the point where it could not produce enough food to feed everyone.

  • Malthus saw was that food production did grow over time but in a slow arithmetic manner, while human population grows exponentially

  • As new food products and methods were adopted, another large volume of food would be added to global production and supply

  • This meant that food production has continued to stay ahead of population growth.

• The science of genetics did not make any impact on global food production until the 1950s

• Neo-Malthusians warn that a Malthusian catastrophe could still occur.

1. Sustainability. If too many of the world’s current growing areas are damaged, can food production keep up with the increased demand?

2. Increasing Per Capita Demand. Can the planet provide enough food when all 10 billion of us eat like the First World does today?

3. Natural Resource Depletion**.** Can a world with 10 billion people have enough material to house everyone, enough fuel to heat all the houses, and enough food to feed everyone?

Population Pyramids

• Graphical way to visualize the population structure of a country or place as well as the gender and age distribution of the population

General Principles:

• Males are always on the left of the pyramid and females are on the right

• Each bar is an age cohort, generally made up of five-year sets

• The origin (0-value) of each bar graph is the center and increases in value as you move left or right outward from the center

• A gap in data for both males and females is likely a sign of past war inside that country, epidemic disease, or famine.

• The general shape of the pyramid is reveals the character of the country, state, province, or city that is being diagrammed.

• increased mortality from disease and old age causes significant declines in the elder population, causing the top to shrink

• Population density is calculated in two main ways.

  • Arithmetic density is the number of people per square unit of land

  • Physiologic density is the number of people per square unit of farmland

    • Important in understanding the geography of countries where the amount of arable land is limited

• The population center of a country is found by averaging the spatial weight of population across the country.

• Overpopulation is a major concern both in resource-poor regions and across the globe.

  • Nonrenewable energy sources will be depleted if conservation efforts and population control methods are not mandated by governments

    • Alleviating concerns over decreasing amounts of personal space

Migration

• Migrants are generally those who voluntarily move from location to location.

• Many countries experience internal migrations that significantly change the countries’ population distributions.

  • Interregional, or internal, migrants: those who move from one region of the country to another

  • Transnational migration: occurs when migrants move from one country to another.

  • Forced migration: people may be taken or coerced from their homes for forced labor through human trafficking or enslavement

  • Undocumented immigrants: people who come seeking refuge or employment opportunities but do not have government authorization

  • Amnesty programs: allow undocumented immigrants the opportunity to apply for official status or citizenship without facing arrest or deportation

  • Step migration: occurs when people move up in a hierarchy of locations, with each move to a more advantageous or economically prosperous place

  • Chain migration: occurs when a pioneering individual or group settles in a new place, establishing a new migrant foothold.

  • Life-course changes: when people move because of major changes in the course of their lives.

Push and Pull Factors

• Push factors are specific things about the rural agricultural landscape and livelihood that force people off the farm

  • (ex: armed conflict, environmental pollution, increased land costs)

• Pull factors are specific things about cities that draw people to the urban landscape

  • (ex: job opportunities, medical care, education, service access, entertainment)