Population Change
Explain population trends and patterns in births (Crude Birth Rate), natural increase and mortality (Crude Death Rate, infant and child mortality rates), fertility and life expectancy in contrasting regions of the world.
Natural Increase
The percentage growth of a population, measured by crude birth rate minus death rate divided by 10.
Population Growth Rate
The percentage growth of a population, measured by crude birth rate minus crude death rate AND the immigrants minus emigrants.
Crude Birth Rate
The number of live births per 1,000 people per year.
Total Fertility Rate
The number of births per thousand women, measured by the number of births divided by women between 15-49 years old x 1,000 per year.
General Fertility Rate
A longer term measure – the average number of children born to a woman in her lifetime.
Crude Death Rate
The number of deaths per 1,000 people per year.
Life Expectancy
The average number of years a person is expected to live.
Infant Mortality Rate
The number of deaths of children before their first birthday per 1,000 live births a year. It is measured by total number of deaths of children divided by total number of live births x 1,000.
Dependency Ratio
The balance of working (‘active’) and non-working people in a population. It is measured by children (0-14) and elderly (65+) divided by those of working age x 100 (to make a percentage)
Ageing Ratio
The balance of working (or ‘active’) and elderly people in a population. It is measured by elderly (65+) divided by those of working age x 100.
Replacement Level
The level of fertility that enables enough children to be born to replace the older generations. A total fertility rate of 2.1 is regarded as the minimum replacement level.
Doubling Time
The length of time it takes for a population to double in size, assuming natural increase remains constant. It is measured by 70 divided by the natural increase %.
Population Momentum
The tendency for a population to grow even though the birth rate is falling. It occurs because of a higher concentration of people in pre-childbearing or childbearing years.
Fertility
Factors Causing High Birth Rates
Mortality
Factors Causing High Mortality Rates
Natural Increase
The percentage growth of a population, measured by crude birth rate minus death rate divided by 10.
Population Growth Rate
The percentage growth of a population, measured by crude birth rate minus crude death rate AND the immigrants minus emigrants.
Crude Birth Rate
The number of live births per 1,000 people per year.
Total Fertility Rate
The number of births per thousand women, measured by the number of births divided by women between 15-49 years old x 1,000 per year.
General Fertility Rate
A longer term measure – the average number of children born to a woman in her lifetime.
Crude Death Rate
The number of deaths per 1,000 people per year.
Life Expectancy
The average number of years a person is expected to live.
Infant Mortality Rate
The number of deaths of children before their first birthday per 1,000 live births a year. It is measured by total number of deaths of children divided by total number of live births x 1,000.
Dependency Ratio
The balance of working (‘active’) and non-working people in a population. It is measured by children (0-14) and elderly (65+) divided by those of working age x 100 (to make a percentage)
Ageing Ratio
The balance of working (or ‘active’) and elderly people in a population. It is measured by elderly (65+) divided by those of working age x 100.
Replacement Level
The level of fertility that enables enough children to be born to replace the older generations. A total fertility rate of 2.1 is regarded as the minimum replacement level.
Doubling Time
The length of time it takes for a population to double in size, assuming natural increase remains constant. It is measured by 70 divided by the natural increase %.
Population Momentum
The tendency for a population to grow even though the birth rate is falling. It occurs because of a higher concentration of people in pre-childbearing or childbearing years.
Fertility
Factors Causing High Birth Rates
- Women maintained in traditional role of rearing children and taking care of house
- Primary based economy where children needed to work on land
- 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 need to obtain a male heir
- Pro-natalist policy
- Marriage at a young age
- Religious or legal practices
- Availability and affordability of contraception
- Education about contraception and family planning
- Cost of children
- Reduced infant mortality (less need to have more children to make up for infant death)
- Female emancipation (females are free to obtain an education and work)
- Anti-natalist policy
- Delayed marriage
- Better care for old dependents
- Mechanization of primary sector and shift to secondary and tertiary sectors
Mortality
Factors Causing High Mortality Rates
- War
- Natural disasters like earthquakes, volcanoes, droughts and floods
- Poor medical care
- Diseases
- Shortage of clean water and poor hygiene
- Unhealthy lifestyle
- Improved medical care
- Immunization program (such as small pox)
- Clean and reliable water supply
- Improved diet (higher calorific intake and healthier diet)
- Improved sanitation and hygiene
- Improved exercise
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 are 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 mechanization 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
Analyze Population Pyramids
Population pyramids show the structure of a population in terms of sex and age. By analyzing population pyramids you can see tends in birth rates, death rates and life expectancy.
The population pyramid can be linked to the demographic transition model.
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 are 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 mechanization 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
Analyze Population Pyramids
Population pyramids show the structure of a population in terms of sex and age. By analyzing population pyramids you can see tends in birth rates, death rates and life expectancy.
The population pyramid can be linked to the demographic transition model.
Population Structure: The composition of the population by age groups. 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.
Case Study - Japan 2010
Sex ratio: The ration between the number of males in a population and the number of females in a population.
Case Study - Japan 2010
Japan is in stage 5 of the demographic transition model (DTM). The population pyramid shows a high life expectancy and low and declining birth rates. The high life expectancy can be seen by the size of the 80+ age group. With an increased elderly population, there will also be an increasing high death rate. Birth rates are decreasing as the size of 35-39 population groups is much larger than the 0-4 group. This indicates that fewer babies are being born.
Case Study - El Salvador 2010
Case Study - El Salvador 2010
El Salvador is in stage 3 of the DTM. It can be seen that El Salvador’s pyramid shows a high birth rate as the 0-4 age group has the largest population and the size decreases as age goes up. Due to the large young people El Salvador, it will probably suffer from population momentum for years to come even if the total fertility rate falls.
Explain population momentum and its impact on population projections. A prediction of future population change 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:
Explain population momentum and its impact on population projections. A prediction of future population change 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