IB Notes

Populations in transition

INTRODUCTION

The world population is growing exponentially because it is accelerating.

Up to 95% population growth is taking place in LEDCs.

Problems associated with fast growth: Pressure on governments to provide for people, destruction of the environment, increased risk of famine & malnutrition, larger rich to poor imbalance in countries.

 

DEFINITIONS

- Crude birth rate: The number of births per 1000 people in a population.

- Crude death rate: The number of deaths per 1000 people in a population.

- Annual growth rate: Found by subtracting the crude death rate from the crude birth rate and is expressed as a percentage.

- Mortality rate: The number of deaths per 1000 people in a population.

- Infant mortality rate: The number of deaths of children less than 1 year old per 1000 live births.

- Child mortality rate: The number of deaths of children less than 5 years old per 1000 live births.

- Age specific birth rate: The number of birth per 1000 of population for a specific age group. 

- General fertility rate: The number of births per 1000 women of childbearing age (15-49 years).

- Total fertility rate: The average number of births per 1000 women of childbearing age.

- Life expectancy: The average number of years a person is expected to live if demographic factors remain unchanged.

- Natural increase / decrease: The difference in crude birth rate and crude death rate over the course of 1 year.

 

HOW TO CALCULATE ANNUAL GROWTH

For example a country had a crude birth rate of 25 and a crude death rate of 20.

(0.025%) - (0.020%) =  (0.005%) 

OR

(0.25‰) - (0.20‰) = (0.05‰)

 

HOW TO CALCULATE CRUDE BIRTH RATE (expressed as a %)

total number of births x 1000

total populaton

 

HOW TO CALCULATE AGE SPECIFIC BIRTH RATE

number of births x 1000

women of any age group

 

HOW TO CALCULATE CHILD MORTALITY RATE

total number of deaths of children aged 1 - 5 years x 1000

total number of children aged 1 - 5 years

 

HOW TO CALCULATE INFANT MORTALITY RATE

total number of deaths of children aged <1 year x 1000

total number of live births

 

CHANGES IN FERTILITY

Factors affecting fertility: Economic, sociocultural and environmental.

 

ECONOMIC FACTORS

- Economic state: If the economy is suffering from high inflation and prices continue to rise, adults may not be able to afford to bring up a child.

- Economic development: If the country is an LEDC, there will be a higher fertility rate due to high mortality rates and poverty. 

 

SOCIOCULTURAL FACTORS

- Prestige: A large family can be considered as prestigious in some countries. Some families may also want to continue the family name.

- Status of women: More women are now joining the work force resulting in later marriages and less time to take care of a child.

- Education: As countries become more developed, people become more educated and learn about different methods of contraception and family planning.

- Residence: People living in rural areas tend to have more children. This is because some women are not allowed to work, families are often poor and are in need of a larger source of income. They are not educated as well and policies such as anti-natalist ones may not apply to them. Their standards of living are often low meaning a higher child mortality rate and parents will need to give birth to more children to replace the dead ones.

- Religion: Some religions are against the use of contraceptive methods such as birth control and sterilization. Most people in MEDCs do not follow these beliefs but some still do in LEDCs.

- Standard of living: A high standard of living means a lower child mortality rate and parents do not have to give birth to more children to replace the dead ones. Families are often richer and they do not need many children in order to support the family. Most children will also go to school as opposed to working from a young age.

- Need for children: More children are needed to support low income earning families. Agriculture and other primary sector occupations play a large role in LEDCs, these are mostly labor intensive so more children are needed to work there.

- Level of income: Low income earning families with limited resources or ambitions will often have the most children. Middle income earning families with high aspirations but limited means tend to have the smallest families. Affluent people can afford large families.

- National policy: Policies such as anti-natalist and pro-natalist policies can affect the fertlity rate as there are fines and rewards that come with it.

- Infant and child mortality: A high child mortality rate will usually result in a high fertility rate.

- Cost to bring up: As the cost to bring up a child is continuously increasing, the fertility rate is going down in many developed nations.

 

ENVIRONMENTAL FACTORS

- Disease: In many LEDCs, diseased such as HIV & AIDS, malaria, cholora and diarrhoea and major killers of children. As a result, parents give birth to more babies.

- Living environment: Risk of natural disasters, climate and soil fertility (for agriculture) can affect the child mortality rate.

 

CHANGES IN MORTALITY

Mortality rate is expected to decrease while life expectancy is expected to increase as a country becomes more developed.

There is often a high number of infant mortality rates in LEDCs due to lack of hygiene, technology, medication, expertise, food, clean water etc. The causes of infant deaths are often preventable.

 

DECREASE IN LIFE EXPECTANCY:

- HIV / AIDS / other life threatening diseases

- War

- Living enviroment  (pollution and overcrowding)

- Poverty

- Malnutrition

- Climate change (drought and desertification)

 

INCREASE IN LIFE EXPECTANCY

- Improvement in healthcare & medicine

- Advanced technology

- Availability of food (and how healthy it is)

- Access to basic necessities (clean water and sanitation)

 

VARIATIONS IN MORTALITY RATE

- Age structure: Areas with a high life expectancy and a high elderly population will have a higher crude death rate than countries with a large young population.

- Social & racial class: The poorer people within a population are usually faced with higer mortality rates. 

- Occupation: Some jobs like mitary and construction can be very dangerous. Diseases may be linked to some jobs like respiratory disease and mining.

- Residence: People living in rural areas and the inner city (facing pollution, overcrowding, stress, poverty) usually suffer from lower standards of living and so, mortality rates are higher.

 

DEMOGRAPHIC TRANSITION MODEL

This is a geographical model used to explain the process of change from high to low birth & death rates as part of the economic development of a country from a pre-industrialized to an industrialized economy.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

- We may see a natural decrease if a large proportion of the population is old as death rates will increase.

- Limitations to the model include: This may not apply to LEDCs due to different resources & wealth and it doesn't account for the recent phonomena such as AIDS.

 

POPULATION MOMENTUM

Population momentum refers to a poplation achieving replacement fertility (if couples have enough children to replace themselves and the dying people) but will continue to have a natural increase in population for several more decades before experiencing a decline in total population.

 

Population momentum factor: Crude birth rate x life expectancy at birth x 100

 

A PMF = 1 means a natural increase is not contributing to population growth.

A PMF > 1 means a positive momentum and growing population.

A PMF < 1 means a negative momentum and shrinking population.

 

UK has a PMF of 1.027 and Sweden has a PMF of 0.738 so they have quite a stable population.

Although the crude birth rate may be same in several countries, the life expectancy can gretly affect the value of the PMF.

PMFs might change in the future as a country becomes more developed. The population in LEDCs will stabalize while in MEDCs it will decrease.

 

POPULATION PYRAMIDS

Population pyramids can display the structure of age, sex, and one more factor (such as race or disease) of people within an area.

Population projections are predictions about the future population based on trends in fertility, mortaliy and migration.

Can help planners to estimate the number of services and facilities needed in the future.

 

 

 

 

 

 

 

 

 

 

STAGE 1

- Wide base: High birth rate and many young dependants

- Concave slope: High death rate

- Short pyramid: Short life expectancy

 

STAGE 2

- Steeper slope: Lower death rate and child mortality rate

- Bulging or indents (usually on the male side): High migration or emmigration levels. May indicate age or sex specific deaths (epidemics or war).

- Taller pyramid: Higher life expectancy

- Larger working population

 

STAGE 3

- Steep slope: Low fertility and low mortality

- Rounded top: High life expectancy

- Growing elderly and dependant population

- Large working population

- Bulging or indents: Sex imbalance

- Taller pyramid

 

STAGE 4

- Nearly vertical sides: Low mortality, low fertility and high life expectancy.

- Rounded and widening top: Ageing population

- Narrowing base: Low fertility (could be below replacement level)

- Shrinking workforce

- Bulging or indents

- Large dependant population

- Taller pyramid

 

GROWTH RATE

-  An annual percentage change in a country's population. Useful to plan the allocation of resources and the future of the economy.

 

DOUBLING TIME

- The time it takes for a country's population to double assuming its natural growth rate remains constant. 

- Doubling time = 70 ÷ growth rate

 

YOUTHFUL AND AGEING POPULATIONS

LEDCs usually have youthful populations while MEDCs have ageing population.

Can use policies and schemes to control or influence population groups.

 

DEPENDENCY RATIO

population <15 - >59

population aged 16 - 59

 

ADVANTAGES OF A YOUTHFUL POPULATION

- Large potential workforce

- Increased income for families

- Source of innovation and ideas

- Faster workers, hence improving productivity and efficiency

- Development of services such as schools

- Create jobs such as teachers and tutors

 

DISADVANTAGES OF A YOUTHFUL  POPULATION

- Cost of supporting schools and clinics (may be compensated for in the future)

- Lack of food, housing, clean water and other necessities / resources to support a growing population

- If high rates of population growth leads to poverty, there may be a higher crime rate.

- High unemployment rate (uneducated, inexperienced and unskilled compared to older workers)

 

ADVANTAGES OF AN AGEING POPULATION

- They are more skilled and experienced: More productive than younger workers

- Can look after children: Allows both parents to work, encourages parents to have more children

- The 'grey' economy expands industries such as medical, healthcare and tourism. They may have a lot of disposable income to spend.

 

DISADVANTAGES OF AN AGEING POPULATION

- More money spent on hospitals 

- Lack of nursing homes and hospitals

- Less money invested in jobs, industry and trading

- Shrinking working population

- Pressure on givernments to raise tax: Cost of funding pensions and healthcare.

- Less efficient or productive workforce as older people may think and work slower.

- Higer rate of poverty: Many do not have jobs or sufficient skills & knowledge. They do not have a source of income.

- Decreasing worker to elderly ratio: Deterioration of the economy.