8.1 - Human population dynamics

Crude birth rate

Crude birth rate

The number of births per thousand individuals in a population per year

Crude death rate

The number of deaths per thousand individuals in a population per year

Natural Increase Rate

The rate of human growth expressed as a percentage change per year

= (Crude birth rate - crude death rate) / 10

Doubling time

The time in years that it takes for a population to double in size

Human Development Index (HDI)

Adopted by the UN Development Programme as a measure of the “well-being” of a country. It combines the health, wealth and education into one value.

Features in MEDCs

• Industrialized nations with high GDPs

• Population is relatively rich

• Individuals are unlikely to starve through poverty

• Relatively high level of resource use per person

• Relatively low population growth rates largely due to low CBR but rising CDRs

• Have very high carbon and ecological footprints

Japan, North America, Europe

Features of LEDCs

• Less industrialized

• May have raw materials (natural capital) but this tends to be exported and processed in MEDCs

• Population has a lower GDP and higher poverty rates

• More people are poor with low standards of living

• High population growth rates largely due to rapidly falling CDRs

• Have lower carbon and ecological footprints

Demography

The study of the statistical characteristics of human populations.

Eg; total size, age and sex composition

Malthusian Theory

Believed that the human population increases geometrically whereas food supplies can grow only arithmetically. Food production can only increase to a certain level determined by the productive capacity of the land and existing levels of technology. According to this thoery, whenever population outstripped food supply ‘natural checks’ would happen. This meant population went down to a manageable level.

Limitations of Malthusian Theory

• Too simplistic - ignores that it is actually only the poor who go hungry

• Did not foresee food production technology advancements

Boserup’s theory

Asserted that an increase in population would stimulate technologists to increase food production. Any rise in the population will increase the demand for food and so act as an incentive to change agrarian technology and produce more food

Limitations of Boserup’s theory

• Is based on the assumption of a “closed” community, not reality

• Overpopulation can lead to unsuitable farming practices that may degrade the land

Why do people have large families

• High infant and childhood mortality

• Security in old age

• Children are an economic asset

• Status of women

• Unavailability of contraceptives

Ways to reduce family size

• Provide education

• Improve health

• Make contraceptives available

• Enhance Income

• Improve resource management

Demographic transition model (DTM)

The pattern of decline in mortality and fertility of a country as a result of social and economic development. A 5-stage population model

Stage 1 of the DTM

High stationary (pre-industrial societies)

• High birth rate due to no birth control

• High infant mortality rates

• Cultural factors encouraging large families

• High death rates due to disease, famine, poor hygiene, and little medicine

Birth rate: High

Death rate: High

Natural Increase: Stable or slow increase

Stage 2 of the DTM

Early expanding (LEDC’s)

• Death rate drops as sanitation and food improve

• Disease is reduced so lifespan increases

• Birth rate is still high so population expands rapidly and child mortality falls due to improved medicine

Birth rate: High

Death rate: Falls rapidly

Natural increase: Very rapid increase

Stage 3 of the DTM

Late expanding (Wealthier LEDC’s)

• Birth rates fall due to access to contraception, improved healthcare, education, emancipation of women

• Population begins to level off and desire for material goods and low infant death rates mean that people have smaller families

Birth rate: Falling

Death rate: Falls more slowly

Natural Increase: Increase slows down

Stage 4 of the DTM

Low Stationary (MEDC’s)

• Low birth and death rates

• Industrialized countries

• Stable population sizes

Birth rate: Low

Death rate: Low

Natural Increase: Falling then stable

Stage 5 of the DTM

Declining (MEDCs)

• Population may not be replaced as fertility rate is low

• Problems of ageing workforce

Birth rate: Rising Again

Death rate: Low

Natural increase: Stable or slow increase

Limitations of Demographic Transition Model (DTM)

• Initial model was without the fifth stage

• The fall in the death rate has not always been as steep as this suggests

• Does not take into account situations such as pandemics, wars, aids

• Eurocentric model and assumes that all countries will become industrialized

Policies that may reduce population growth rates

• Parents in subsistence (supporting themselves at minimum level) may be dependent on their children for support in their later years and this may create an incentive to heave many children

  • if the government introduces pension schemes, the CBR comes down

• If you have to pay more tax to have more children, you may decide to have a smaller family

• Policies that stimulate economic growth may reduce birth rates as a result of increased access to education about methods of birth control

• Urbanization may be a factor as fewer people can live in the smaller urban accommodation

• Policide directed toward the education of women and enabling women to have greater personal and economic independence may be the most effective in reducing fertility and therefore, population pressures

Policies that may increase population growth rates

• Agricultural development, improved public health, sanitation, etc. may lower death rates and stimulate rapid growth without significantly affecting fertility

• Lowering income tax or giving incentives and free education and health care may increase birth rates (Ex. Australia Baby Bonus)

• Encouraging immigration particularly for workers (Ex. Russia allows migrants to work who do not have the qualifications to fill the gap in manual labor)