Changing populations and places

World Population growth rate

World population growth

World population growth is increasing, and is already causing many problems. It is projected to continue growing in some parts of the world whilst others stabilize, with some estimates putting the final population of the world as high as 12 billion (it is currently half that). The latest official current world population estimate, for November 2012, is estimated at 7 billion. The areas of high population growth include Asia, Africa and Latin America.

Current World Population

Most populous nation: Should India rejoice or panic?

Population growth over time

  • —It took over 1m years for the world’s population to reach 1 billion. (1830)
  • —Then it took 100yrs to reach 2billion in 1930
  • —Took 30yrs to reach the 3rd billion in 1960
  • —15yrs to reach the fourth billion in 1975 and
  • —12yrs to reach the 5th billion 1987
  • —The 6th billion also took 12yrs in 1999
  • —This shows that world population growth has slowed down.

Demographic Transition Model
—Over the past 300 years, population demographics have continued to evolve as a result of the relationship between birth and death rates within a country. The observation and documentation of this global phenomenon have produced a model, the Demographic Transition Model, which helps explain and make sense of changes in population demographics.

It describes the way the total population of a country changes over time, taking into consideration birth and death rates. —The model suggests that mortality and fertility would decline as a result of social and economic development. It predicts that all countries would go through four demographic transition stages over time.

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STAGE 1– High Stationary or Pre-Industrial

  • Birth Rate High
  • Death Rate High
  • Natural Increase Low
  • Fertility Rate High
  • Life expectancy is low
  • Infant Mortality Rate High
  • —Examples: Various isolated communities in the least developed regions of Africa; war-torn regions (eg Afghanistan, Sudan, Angola); political hotspots (eg North Korea)
  • —Other Characteristics: Characterizes pre-industrial societies. Most of the population is rural and involved in subsistence agriculture.

Reasons for High Birthrate:

  • Little or no family planning
  • Parents have many children because of high infant mortality
  • Many children are needed to work the farm(a cheap source of labor)
  • Children are a sign of virility
  • Some religious beliefs and cultural traditions encourage large families
  • Lack of education, meaning many girls do not go to school, thereby getting married at an early age. This leads to high fertility rate
  • Women not having a say in the number of children they can have
  • Lack of material ambition – women, therefore, see many children as a source of ‘wealth’.
Population Pyramid for Stage 1

Reasons for High Death Rate:

  • Disease and plague (e.g. bubonic, cholera, kwashiorkor)
  • Famine, uncertain food supplies, and poor diet
  • Poor hygiene/sanitation, no piped clean water or sewage disposal
  • Poor housing, thereby exposing children to mosquitoes and subsequently malaria
  • Poor access to medical health care, including medical personnel in both urban and rural areas
  • Poor transport network, meaning doctors/nurses are not able to reach rural areas to treat basic diseases such as malaria, cholera and other infant-killer diseases

—STAGE 2– Early Expanding or Early Industrial

  • high birthrates
  • falling death rates
  • Natural Increase is rising steadily
  • Fertility Rate High
  • Infant Mortality Rate High
  • Life expectancy is rising steadily
  • Example: Sub-Saharan Africa
  • Other Characteristics: Characterizes post-industrial societies.
  • Most of the population is rural, but urbanization is increasing rapidly. Dependency load begins to increase rapidly as the young cohort (%<15 yrs old) begins to dominate the proportion of the population.
Population Pyramid for Stage 2

Reasons for high birth rates are the same as stage 1
Reasons for falling death rates

  • improved medical care e.g. vaccinations, hospitals, doctors, new drugs, and scientific inventions
  • Improved sanitation and water supply
  • Improvements in food production in terms of quality and quantity
  • Improved transport to move food and doctors

—STAGE 3– Late Expanding or Late Industrial

  • —falling birth rate
  • Life expectancy is high and rising
  • low death rate
  • total population growing, but slowly
  • Examples: India and Brazil

Reasons for falling birth rates

  • Family Planning utilized; contraceptives, abortions, sterilization, and other government incentives adopted
  • A lower infant mortality rate means less pressure to have children in the hope that if some die some will survive
  • Increased mechanization and industrialization mean less need for labour
  • Increased desire for material possessions and less desire for large families, due to the high cost of raising children
  • Emancipation of women, meaning women have a say in the number of children they want to have in a marriage, they can decide at what age and to whom they want to marry etc.
  • Education of women, hence they spend marriage years in school and know the consequences of having unwanted children.
  • Government policies to reduce the birth rate. eg. China’s One-Child Policy.

Late Stage 3

Population Pyramid for Stage 3
  • Birth Rate Decreasing to a manageable level
  • Death Rate Low
  • Natural Increase Decreasing sharply
  • Fertility Rate Decreasing sharply
  • Life expectancy is high
  • Infant Mortality Rate Lowered
  • Example Region Latin America, Tiger Economies
  • Other Characteristics: Ends the population explosion. People choose smaller families due to many social and economic factors. Urbanization dominates. Population stabilization begins. Population continues to grow due to the large young population reaching childbearing age.

—STAGE 4– Low Stationary or Low Fluctuating

Population Pyramid for Stage 4
  • —birth rate is low
  • death rate has fallen
  • total population is high and stationary
  • life expectancy is very high
  • Example: United States and Canada

Reasons for low death rates:

  • improved medical care e.g. vaccinations, hospitals, doctors, new drugs, and scientific inventions
  • Improved sanitation and water supply
  • Improvements in food production in terms of quality and quantity
  • Improved transport to move food and doctors

Reasons for low birth rate:

  • Family Planning utilized; contraceptives, abortions, sterilization, and other government incentives adopted
  • A lower infant mortality rate means less pressure to have children in the hope that if some die some will survive
  • Increased mechanization and industrialization mean less need for labour
  • Increased desire for material possessions and less desire for large families, due to the high cost of raising children
  • Emancipation of women, meaning women have a say in the number of children they want to have in a marriage, they can decide at what age and to whom they want to marry etc.
  • Education of women, hence they spend marriage years in school and know the consequences of having unwanted children.
  • Government policies to reduce birth rate. eg. China’s One-Child Policy.

—Criticism of the DTM

  1. The DTM is too generalized because it assumes that every country falls into a specific stage on the model. E.g Cuba falls on stage 4 of the model in terms of health indicators but it has a high birth rate which is not typical for a country in stage 4 of DTM.
  2. It is too Eurocentric – based on Europe, and presumed that all countries will follow a similar pattern of socioeconomic development. This may not be the case. For example, in less developed countries, death rates are more rapid than in HIC countries.
  3. It does not include the impacts of migration, which is a major component of population change.
  4. It does not take into account the role of governments in bringing about population change. For example, the government-sponsored, nationwide, family planning program in Malaysia has reduced birth rates faster than the DTM predicted. Also, China introduced the One-Child policy, forcing it into stage three.

The usefulness of the DTM

  1. It is simple and easy to understand
  2. It enables comparisons to be made demographically between countries
  3. The timescale of each stage is flexible. For example, the UK took over 100 years to complete stage 2, as social, economic and technological changes were introduced gradually and death rates fell slowly.
  4. It is useful for making predictions of the level of economic development or growth of a country in the future.
  5. The DTM can be applied to developed and developing countries in trying to understand and explain population change. E.g The DTM explains changes in birth and death rates in developing and developed countries.

For more on each stage of the Demographic Transition Model visit this website: Population Education. It provides details of case studies and reasons to explain each stage.

Natural Increase:

It is an increase in population due to an increase birth rate over the death rate.

  • Natural Increase=Birth rate – death rate. If the answer is a positive figure then there is a natural increase

Natural Decrease: This is a situation in which the death rate exceeds the birth rate.

  • Natural decrease =BR<DR or ND= BR-DR  if it is negative, there is natural decrease ie. death rate is greater than birth rate

Population Projection: This is an estimate of the future population of a country based on current age-gender structure, mortality and migration.

Doubling Time: This is the time taken for a population to double assuming  natural growth rate is constant.

Population Momentum: This is the tendency for a population to grow despite falling birth and fertility rates.

Advantages of Population Projection

  • Helps countries design policies that will either increase or decrease population.
  • Will help a country know critical sectors that can guide the government in the allocation of resources.
  • It is useful for businessmen and investors to understand the investment climate in the country.
  • Helps the government in estimating the country’s future income through taxation
  • It is useful to the UN and other NGO’s in recognizing the need for aid in a country.

Fertility Rate:

Fertility rate is the average number of children a woman can have in her lifetime. Fertility can be measured using the Total fertility rate and crude birth rate

  • Total fertility rate is the average number of births per 1000 women of childbearing age. Generally, fertility rates are high in LIC’s relatively high in MIC’s and low in HIC’s.
  • Crude birth rate: The total number of live births per 1000 population per year. Birth Rate: The total number of live births per 1000 women per year.

Fertility rate (total births er woman): World Bank

Fertility rate: ‘Jaw-dropping’ global crash in children being born

Factors affecting fertility:

  • The level of female education i.e. if women are educated, the fertility rate will be low because they spend their time in school. Female education also leads to females’ gaining knowledge in the use of contraceptives, therefore reducing the fertility rate.
  • Place of residence: In urban areas, women tend to have fewer children because of the high costs of raising them. On the other hand, women in rural areas tend to have many children as a sign of virility or a source of cheap labor.
  • Emancipation of women. In societies where women have a high status, they are emancipated and can decide on the number of children they desire. The opposite is true for societies where women are restricted.
  • Religion plays a key role in determining the level of fertility. Catholics and Islamic religion encourage large families
  • Government policy: If the government decides on a pro-natalist ( will increase fertility) or anti-natalist policy ( decrease fertility), it will affect the level of fertility positively or negatively.
  • Level of contraceptive use: when a lot of people in a country use contraceptives effectively it would lower the fertility rate and vice versa.

Crude Death rate:

Crude death rate refers to the total number of deaths per 1000 people in a year. Death rate can be measured using Infant mortality rate, Child mortality rate, Crude death rate and Life expectancy.

  • Child mortality rate: Child mortality rate is the number of children dying before reaching five years of age, per 1,000 live births in a given year.
  • Infant mortality rate: Infant mortality rate is the number of infants dying before reaching one year of age, per 1,000 live births in a given year.
  • Crude death rate: crude death rate indicates the number of deaths per 1,000 population in a given year. Subtracting the crude death rate from the crude birth rate provides the rate of natural increase, which is equal to the rate of population change in the absence of migration.
  • Life expectancy: the average number of years a person is expected to live.

Map of Crude death rate in the world: World Bank Report

Factors affecting death rate:

  • Type of residence: People living in slums and poor housing conditions are living to suffer from diseases of poverty such as cholera, malaria etc compared with those living in better housing conditions
  • Occupation: Some occupations are high-risk jobs. These may include mining, construction and those exposed to hazardous chemicals, hence they are more likely to die. On the other hand, professions such as nursing, teaching, banking etc are less likely to die due to occupational hazards.
  • Social Class: A person’s social class can determine their life expectancy. People with a high social class are more likely to be richer and well-educated. They are therefore more like to over diseases of poverty, compared with those with a low social class (more likely to be poorer, less educated and lack the knowledge and resources to meet their health needs)
  • Age structure: A country with an ageing population is more like to suffer from chronic diseases or may die from natural causes than countries with a large youthful population.

Life expectancy:

Life expectancy refers to the average number of years that a person is expected to live at the time of their birth. Life expectancy has increased over the years in many parts of the world since 1950. Differences, however, occur in the pattern and distribution of Life Expectancy. Africans can live an average of 52yrs, Asians 66 and South Americans 69.

Life Expectancy for advanced countries like US is 79, EU 75, Canada 80. Japan has the highest of about 83yrs. This shows that LE is increasing globally, except in most African countries.

Variations in Life expectancy may also occur in some cultures. E.g in Infant mortality rate in SA is higher among Blacks than infant mortality rate among the White population. Also, in Brazil Life Expectancy among affluent Brazilians is higher than among the poor living in shanty towns.

The causes of such an increase in life expectancy include;

  • improved food production (both in quality and quantity), through mechanisation and the introduction of high-yielding varieties of food
  • better hygiene, meaning diseases such as cholera and other diseases related to poor hygiene are eliminated.
  • greater availability of clean water
  • better health care delivery: ie there is an improvement in the technology and infrastructure, hence health care is more efficient and reliable i.e drones will be able to transport blood supplies, thus, reducing death in rural areas.
  • improvement in housing- leads to a reduction in diseases associated with leaving in under poor conditions.

Life Expectancy worldwide

Population Structures:

The structure of a population refers to the distribution of a population according to age and sex characteristics. The population of a country can be categorized under the following:

  • Youthful population ( 0 – 14 years)
  • Working/economically active population (15-64)
  • Ageing population (65+)

These characteristics differ from country to country. Generally, LICs have population pyramids with the following characteristics:
Ghana’s population pyramid – 2019
  • It has a broad base, indicating the high birth rate
  • The proportion of males and females is more or less equal
  • The pyramid tapers away to the higher age groups due to high death rate and low life expectancy

The population pyramid for a HIC is characterized by:

  • Narrow base, indicating low birth rate
  • bulging working population, indicating migration of foreigners into the country
  • Heavy top, indicating a large ageing population
  • In general, the pyramid is bell-shaped
Population Pyramid for the United Kingdom, 2019

Relationship between Demographic Transition and Population Structure

There is a correlation between the level of economic development and the population pyramid of a country. In other words, the stages of the DTM correspond with the shape of the population pyramid for any given country.

Source: Wikipedia

The link below shows the population pyramid for each country:

Population pyramid for various countries

Youthful Population:

This refers to a population structure in which there are usually a large proportion of young people in a country within the age range of 0 and 14 years. This is caused by:

  • Lack of family planning methods
  • Many children are seen as a sign of virility
  • A high infant mortality rate leads to mothers giving birth multiple times to increase the chance of some children surviving.
  • All the other reasons stated for the high birth rate in Stage I of the DTM can be applied here

Examples of countries with high youthful populations are India and Uganda as well as all other LEDCs which are noted for their high birth rates.

Advantages of Large Youthful Population

  • Large potential workforce
  • Investment in the economy
  • Increase in the quality of healthcare and services
  • The vibrant ideas of the young serve as a source of new innovations and ideas
  • Large potential market for selected goods

However, it comes with disadvantages

  • Cost of supporting schools and clinics
  • Investment in primary education
  • Need to provide sufficient food housing and water to a growing population eg Rio de Janeiro
  • High rates of unemployment
  • Large numbers living in poor-quality housing
  • High crime rates
  • High rates of population growth
Managing Gambia’s Youthful Population

Dependency Ratio:

The dependent population refers to the group of people between the ages of 0-14 and 64+. It is the Youthful population + Ageing population. The dependency ratio is the ratio of the dependent population to the working population.

DR=0-14 +64+/ 15-63 or Youthful population +ageing population divided by the working population.

There are two main kinds of dependents. These are:

  • Young dependents: a country with a large percentage of its dependents within the 0-14 years bracket. This is typical of LICs such as Ghana, Kenya, and Uganda. The formula: 0-14/15-64*100.
  • Old-age dependents: old-age dependents refer to a country with a large number of dependents who are 64+. This is typical of HIC like Germany, Italy, USA. The formula: 65+/15-64*100.

In both LICs and HICs, the dependency ratio is generally high due to the following reasons:

  • Falling death rate in both LICs and HICs, hence an increase in total population
  • High life expectancy, meaning more mouths to feed
  • Increasing the number of emigrants coming to a country as dependents
  • High birth rate in LIC, leading to an increase in the number of young dependents

Limitations of the dependency ratio:

  • This is a crude measure because the working population may include students and disabled people who might not be earning any income.
  • Also, some people in the ageing population continue to work until their bodies cannot support them
  • Some youth may also be working, yet these may not be included in the computation of the dependent population
pyramid for young dependents. E.g Congo
pyramid for old dependents. E.g JapanG
Global Age= dependency

The consequences of megacity growth for individuals and societies

The causes and consequences of forced migration and internal displacement

Types of forced migrants

  • Refugees are people who have been forced to leave their country or home to another country. According to the UN High Commissioner for Refugees, there are about 25.9million refugees worldwide
  • Internally displaced people (IDPs) are those leaving their homes due to conflicts or natural disasters. Whilst a person leaving their home for another country is considered a refugee, those leaving their home to settle in their home country are referred to as internally displaced persons.
  • An asylum seeker is someone who has left his or her country to seek protection from another country as a refugee but whose status is yet to be determined.
  • Environmental refugees or displacees are people seeking refuge as a result of environmental or natural disasters.
  • Climate refugees or climate migrants are a subset of environmental migrants who were forced to flee “due to sudden or gradual alterations in the natural environment related to at least one of three impacts of climate change: sea-level rise, extreme weather events, and drought and water scarcity. ”
  • Development Displacees: These are people compelled to move as a result of a developmental project such as the building of a dam or highway etc. example of such is the building of the Akosombo Dam causing the displacement of people.
  • Trafficked People: These are people who have been moved by human traffickers with the promise of lucrative jobs abroad as well as greener pastures but upon arrival, they end up becoming sex slaves etc.

Causes of forced migration

  • Natural disaster such as famine and drought in Chad, Mali, Niger has caused the outmigration of people to the coastal areas such as Ghana, Nigeria and the Ivory Coast and this is most common among Cattle herders.
  • Wars can cause people to move from one place to another in search of security. Examples of such migrations are from Somalia to Kenya and the Eritreans to the United Kingdom.
  • Forced conscription: People move from one place to another due to the chances of being forced to join the military. An example is forced conscription in Syria and Eritrea.
  • Religious persecution is the systematic mistreatment of an individual or group of individuals as a response to their religious beliefs and affiliations or lack thereof. An example of countries is Pakistan and Saudi Arabia.
  • Cultural belief is any belief in an imaginary thing that is considered real by a large group of people and as such the beliefs people attached to their actions may cause the outmigration of people. This is typical of countries that believe in women as inferior or believe in gender inequality or early marriages and Female Genital Mutilation
  • Racial discrimination is any discrimination against individuals on the basis of their skin type, or racial or ethnic origin. Individuals can discriminate by refusing to do business with, socialize with, or share resources with people of a certain group and as a result, individuals move into places they feel accepted.

Yayra Akosua Sosu and Belinda Dzifa Gasu

Examples of forced migration

Syrian Refugees

Causes of forced migration:


4 replies on “Changing populations and places”

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