Annual Growth Rate: This is normally expressed as a percentage and is calculated by subtracting the crude death rate from the crude birth rate. Although the world's population is increasing individual regions or countries can have negative growth. When looking at individual regions or countries growth it is often described as natural increase or natural decrease (natural because it does not include migration). For example if a country had a birth rate of 25 and a death rate of 20, annual growth would be calculated in the following way:
(the percentages are calculated by dividing the birth and death rates by 1000, because birth rates and death rates are measured per 1000 of population)
Crude birth rates (CBR): The number of births per 1,000 of population within a country.
Crude death rates (CDR): The number of death per 1,000 of population within a country.
Population distribution: The way the population is spread out. Population may be distributed evenly (in a regular pattern) or unevenly. Virtually all populations are distributed unevenly because of human and physical factors e.g. availability of water and/or jobs.
Population density: The number of people living per km2. Countries like Singapore and Hong Kong have very high population densities, while countries like Russia, Canada and Australia have quite low population densities.
Remember whenever you are describing a graph or a table you must use figures. Also look for trends, changes in trends and anomalies.
Age specific birth rate: The number of birth per 1000 of population for a specific age group e.g. 20 to 25 year olds.
General fertility rate: The number of births per 1000 women of childbearing age (15-49 years)
Total fertility rate: The number of babies a woman is expected to have in her lifetime. The total fertility rate normally falls as a country develops.
Reproductive age range (or child bearing age): Biologically any women between puberty and menopause can have a child. However, it usually means anyone between the ages of 15 and 49.
Replacement rate: The total fertility rate needed for a country to replace an maintain its population. The replacement rate is about 2.1.
FACTORS CAUSING HIGH BIRTH RATES
FACTORS CAUSING LOW BIRTH RATES
Primary based economy where children are needed to work on land
Women maintained in traditional role of rearing children and taking care of house
Lack of education about contraception and family planning
The need for children to care for elderly residents
Status symbol of having a large family or the need to obtain a male heir
Pro-natalist policy
Religious or legal practices (no abortion or discouragement of using contraception)
Marriage at a young age
Availability and affordability of contraception
Education about contraception and family planning
Reduced infant mortality (less need to have more children to make up for infant deaths)
Female emancipation (females are free to get an education and work)
Cost of children
Anti-natalist policy (like China)
Delayed marriage
Better care for old dependents (less need for children to care for their parents in old age)
Mechanisation of primary sector and shift to secondary and tertiary sectors
Infant mortality rate (IMR): The number of deaths of infants under 1 year old per 1000 live births per year.
Child mortality rate: The number of deaths of children under 5 years old per 1000 children.
Please not that if a baby is aborted, a female miscarries or baby is stillborn, then they are not included in the statistics above.
Age specific death rate: The number of deaths per 1000 of population per year of a specific age group e.g. 50 to 55 year olds.
Life expectancy: The average age someone is expected to live when they are born. Japan has the highest life expectancy in the world.
FACTORS CAUSING HIGH DEATH RATES
FACTORS CAUSING LOW DEATH RATES
War
Natural disasters like earthquakes, volcanoes, droughts and floods
Disease
Poor medical care
Shortage of clean water and poor hygiene
Unhealthy lifestyle
Improved medical care
Immunisation programmes e.g. Small pox
Clean and reliable water supply
Improved diet (higher calorific intake and healthier diet)
Improved sanitation and hygiene
Improved exercise
Explanation of Some Factors Affecting Death Rates and Life Expectancy:
Age: The very young and the very old are most vulnerable to disease, malnourishment and natural disasters and therefore more likely to have a higher incidence of dieing.
Sex: In nearly every country women live longer than men (usually 5-10 years longer). This is not fully understood, but it is believed to be a combination of biological and lifestyle reasons. Women tend to suffer cardiovascular disease later in life and men tend to cause more damage to themselves through drinking and smoking. Why do women live longer than men - TIME article
Residence: The location/country that you are born play a massive role in your life expectancy. If you are born into a developed, literate and peaceful country e.g. Japan your life expectancy is going to be high. However, if you are born into a poor, drought and famine ridden country that is at war e.g. Somalia then your life expectancy is going to be low.
Occupation: Some jobs are more physically or mentally demanding than others and can therefore affect peoples health. A job that keeps people active may prolong health, but if it is active and dangerous like mining, it might shorten life. Some jobs like teaching are said to be stressful and may reduce life expectancy. Why accountants live longer than builders - Telegraph article
Nourishment: If you have a shortage of food (under nourished) you are more vulnerable to disease. If whole countries suffer from famine a country's death rate may dramatically increase - again it will normally be the old and young affected first. Under nourishment is not the only problem, malnourishment can also increase death rates. This is when people are eating a bad diet that may contain too much salt and/or fat.
Accommodation: The quality of your house can play a big factor in your life expectancy. If you live in an informal settlement you are more vulnerable to disease, natural disasters and sometimes crime. However, if you live in a modern structure you will probably enjoy running water, mains electricity and protection from the weather, therefore helping you remain healthy.
Literacy: Your ability to read and write can have a massive influence on your health and life expectancy. Not only does it give you better job prospects, but also allows you to know how to care for yourself i.e. what to eat and what to do if you are ill.
As well as births and deaths, population can also be altered by migration. We will look at migration later, but the key terms to understand in terms of population change are:
Emigration: The migration of people out of a country.
Immigration: The migration of people into a country.
Net migration: The difference between immigration and emigration. If immigration is greater than emigration then you have net migration gain, if emigration is greater than immigration then you have net migration loss.
A good way of looking at correlations between birth and death rates and other variables e.g. GDP per capita or doctors per 1000 of population is to look at the Spearman's coeffecient. To practice Spearman's have a look at the attached exercises:
The demographic transition model, usually just called the DTM shows changes in birth rates, death rates and population growth as a country develops. When the model was first made it only had four stages, but more recently a fifth stage has needed to be added.
STAGE 1: The poorest societies that are usually nomadic hunter gatherer tribes. They have little or no modern medical care and are often in conflict with other tribes. They have no family planning. High birth and death rates means there is no real population growth. STAGE 2: Probably more sedentary living where there is improvements in the provision of food and water, basic medical care may also develop. Birth rates remain high, but because of the lowering death rates the population starts to grow. STAGE 3: As education improves and mechanisation takes place then birth rates begin to fall. However, because birth rates are higher than death rates then the population still grows. STAGE 4: Birth rates and death rates are now both low. Because they are both low, population remains stable. STAGE 5: Recently added to the DTM, here birth rates fall below death rates so the population begins to decline.
This can happen because of the emancipation of females, cost of child care, delayed marriage etc. Countries like Japan are in stage 5.
Demographic Transition Model
Population Pyramids
Population Pyramid: Population pyramids show the structure of a population in terms of sex and age. By analysing population pyramids you can see trends in birth rates, death rates and life expectancy.
Japan 2010: Japan is in stage 5 of the demographic transition model (DTM). The population pyramid shows this with a high life expectancy and low and declining birth rates. You can tell that Japan has a high life expectancy because of the size of the 80+ age group. You can also tell that Japan has declining birth rates because the size of the population groups from 35-39 all the way down to 0-4 are actually getting smaller in size. This means that each year less babies are being born. Interestingly, even though Japan has very high life expectancy it actually has quite high death rates (higher than you would expect). This is because there are so many old people in Japan (all old people die eventually, even if they live to 95).
El Salvador 2010: The El Salvador pyramid is very different to the Japan pyramid and looks more like a stage 3 country. The most noticeable thing from El Salvador's pyramid are its high birth rates. You can tell that El Salvador's birth rates are high and increasing because as you move down the pyramid (through the age groups) the size of them get bigger. Because of the large amount of young people in El Salvador, it will probably suffer from population momentum for many years to come even if the total fertility rate falls.
Population structure: The composition of the population. Although you could divide population be religion, ethnicity, etc. it is usually just done by age and sex. A population pyramids divides the population by these categories.
Sex ratio: The ration between the number of males in a population and the number of females in a population.
Doubling time: The length of time it takes for a population to double in size. It is calculated by dividing 70 by the growth rate (r).
Population momentum: The continued growth of a population after fertility rate is equal or actually below the replacement rate. This is happens if there is a large concentration of people in the reproductive age range.
Population projections: A prediction of future population changes based on current trends of mortality, fertility and migration. The UN uses a number of assumptions when making these predictions (see the summary on the document below). The UN make population projections for a number of reasons, including:
To be able to better allocate and distribute resources
To be able to target family planning and medical care more effectively
To be to predict population crises e.g. famine, refugee problems
To advise government and NGOs (Non-governmental organisations (Charities))
There are a number of factors which may impact population projections for a country, region or the whole world. These include:
War - wars such as the one in Iraq/Syria can kill people leading to rising death rates, but it can also divide families leading to falling birth rates.
Natural disaster - large scale disaster like the Indian Ocean Tsunami (26th December 2004) can raise death rates and again reduce the population in the reproductive age range.
Disease - disease outbreaks like the recent Ebola outbreak in West Africa can increase death rates and reduce birth rates.
New cures - recently there have been trials for malaria vaccines. If these are successful it will drastically reduce death rates. Changes will be equally dramatic if cures are developed for HIV or cancer.
Climate change - may increase the number of refugees and therefore divide families, but it may also reduce the amount of farmland which may lead to famine.
Census: An official population survey carried out by governments (usually every ten years). The census looks at population, but also other socio-economic variables like income, home ownership and ethnicity.
Population change
25 (0.025%) - 20 (0.02%) = 5 (0.005%) X 100 = 0.5%
(the percentages are calculated by dividing the birth and death rates by 1000, because birth rates and death rates are measured per 1000 of population)
Crude birth rates (CBR): The number of births per 1,000 of population within a country.
Crude death rates (CDR): The number of death per 1,000 of population within a country.
Population distribution: The way the population is spread out. Population may be distributed evenly (in a regular pattern) or unevenly. Virtually all populations are distributed unevenly because of human and physical factors e.g. availability of water and/or jobs.
Population density: The number of people living per km2. Countries like Singapore and Hong Kong have very high population densities, while countries like Russia, Canada and Australia have quite low population densities.
Remember whenever you are describing a graph or a table you must use figures. Also look for trends, changes in trends and anomalies.
UN 'concerned' by world population growth trends - BBC article
UK population sees biggest increase in half a century - BBC article
World Population to reach 7 billion - BBC article
The Word at 7 Billion - What Number are you? - BBC article
Fertlity
Age specific birth rate: The number of birth per 1000 of population for a specific age group e.g. 20 to 25 year olds.
General fertility rate: The number of births per 1000 women of childbearing age (15-49 years)
Total fertility rate: The number of babies a woman is expected to have in her lifetime. The total fertility rate normally falls as a country develops.
Reproductive age range (or child bearing age): Biologically any women between puberty and menopause can have a child. However, it usually means anyone between the ages of 15 and 49.
Replacement rate: The total fertility rate needed for a country to replace an maintain its population. The replacement rate is about 2.1.
FACTORS CAUSING HIGH BIRTH RATES
FACTORS CAUSING LOW BIRTH RATES
Australia celebrates baby boom - BBC article
Pope rejects condoms for Africa - BBC article
Philippines contraception law signed by Benigno Aquino - BBC article
Mortality
Infant mortality rate (IMR): The number of deaths of infants under 1 year old per 1000 live births per year.
Child mortality rate: The number of deaths of children under 5 years old per 1000 children.
Please not that if a baby is aborted, a female miscarries or baby is stillborn, then they are not included in the statistics above.
Age specific death rate: The number of deaths per 1000 of population per year of a specific age group e.g. 50 to 55 year olds.
Life expectancy: The average age someone is expected to live when they are born. Japan has the highest life expectancy in the world.
FACTORS CAUSING HIGH DEATH RATES
FACTORS CAUSING LOW DEATH RATES
Explanation of Some Factors Affecting Death Rates and Life Expectancy:
Age: The very young and the very old are most vulnerable to disease, malnourishment and natural disasters and therefore more likely to have a higher incidence of dieing.
Sex: In nearly every country women live longer than men (usually 5-10 years longer). This is not fully understood, but it is believed to be a combination of biological and lifestyle reasons. Women tend to suffer cardiovascular disease later in life and men tend to cause more damage to themselves through drinking and smoking. Why do women live longer than men - TIME article
Residence: The location/country that you are born play a massive role in your life expectancy. If you are born into a developed, literate and peaceful country e.g. Japan your life expectancy is going to be high. However, if you are born into a poor, drought and famine ridden country that is at war e.g. Somalia then your life expectancy is going to be low.
Occupation: Some jobs are more physically or mentally demanding than others and can therefore affect peoples health. A job that keeps people active may prolong health, but if it is active and dangerous like mining, it might shorten life. Some jobs like teaching are said to be stressful and may reduce life expectancy. Why accountants live longer than builders - Telegraph article
Nourishment: If you have a shortage of food (under nourished) you are more vulnerable to disease. If whole countries suffer from famine a country's death rate may dramatically increase - again it will normally be the old and young affected first. Under nourishment is not the only problem, malnourishment can also increase death rates. This is when people are eating a bad diet that may contain too much salt and/or fat.
Accommodation: The quality of your house can play a big factor in your life expectancy. If you live in an informal settlement you are more vulnerable to disease, natural disasters and sometimes crime. However, if you live in a modern structure you will probably enjoy running water, mains electricity and protection from the weather, therefore helping you remain healthy.
Literacy: Your ability to read and write can have a massive influence on your health and life expectancy. Not only does it give you better job prospects, but also allows you to know how to care for yourself i.e. what to eat and what to do if you are ill.
As well as births and deaths, population can also be altered by migration. We will look at migration later, but the key terms to understand in terms of population change are:
Emigration: The migration of people out of a country.
Immigration: The migration of people into a country.
Net migration: The difference between immigration and emigration. If immigration is greater than emigration then you have net migration gain, if emigration is greater than immigration then you have net migration loss.
Life expectancy to soar - BBC article
Warning over infant mortality gap - BBC article
Infant deaths linked to poverty - BBC article
Countries pledge $4.3 billion in funding for child vaccines - BBC article
A good way of looking at correlations between birth and death rates and other variables e.g. GDP per capita or doctors per 1000 of population is to look at the Spearman's coeffecient. To practice Spearman's have a look at the attached exercises:
Demographic Transition Model
STAGE 1: The poorest societies that are usually nomadic hunter gatherer tribes. They have little or no modern medical care and are often in conflict with other tribes. They have no family planning. High birth and death rates means there is no real population growth.
STAGE 2: Probably more sedentary living where there is improvements in the provision of food and water, basic medical care may also develop. Birth rates remain high, but because of the lowering death rates the population starts to grow.
STAGE 3: As education improves and mechanisation takes place then birth rates begin to fall. However, because birth rates are higher than death rates then the population still grows.
STAGE 4: Birth rates and death rates are now both low. Because they are both low, population remains stable.
STAGE 5: Recently added to the DTM, here birth rates fall below death rates so the population begins to decline.
This can happen because of the emancipation of females, cost of child care, delayed marriage etc. Countries like Japan are in stage 5.
Population Pyramids
Population Pyramid: Population pyramids show the structure of a population in terms of sex and age. By analysing population pyramids you can see trends in birth rates, death rates and life expectancy.
El Salvador 2010: The El Salvador pyramid is very different to the Japan pyramid and looks more like a stage 3 country. The most noticeable thing from El Salvador's pyramid are its high birth rates. You can tell that El Salvador's birth rates are high and increasing because as you move down the pyramid (through the age groups) the size of them get bigger. Because of the large amount of young people in El Salvador, it will probably suffer from population momentum for many years to come even if the total fertility rate falls.
Population structure: The composition of the population. Although you could divide population be religion, ethnicity, etc. it is usually just done by age and sex. A population pyramids divides the population by these categories.
Sex ratio: The ration between the number of males in a population and the number of females in a population.
China facing growing gender imbalance - BBC article
Measuring Growth Rates
Growth rate: This is used for calculating the long term growth rate of a country or region. The formula for calculating growth rate is below.
India to overtake China as biggest population by 2026 - Telegraph article
Doubling time: The length of time it takes for a population to double in size. It is calculated by dividing 70 by the growth rate (r).
Population momentum: The continued growth of a population after fertility rate is equal or actually below the replacement rate. This is happens if there is a large concentration of people in the reproductive age range.
Population projections: A prediction of future population changes based on current trends of mortality, fertility and migration. The UN uses a number of assumptions when making these predictions (see the summary on the document below). The UN make population projections for a number of reasons, including:
There are a number of factors which may impact population projections for a country, region or the whole world. These include:
You can look at the UN's population prospects and projections at the following website: UN Population Projections
Global Population to pass 10 billion by 2100 - UN News
Census: An official population survey carried out by governments (usually every ten years). The census looks at population, but also other socio-economic variables like income, home ownership and ethnicity.
China's census shows population ageing and urbanising - BBC article