Ch. 2 Population Sec. 2.3 - Demographic Transition Model
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AP Human Geography Key Issue 2-3 Why Is Population Increasing at Different Rates in Different Countries?
Variations in Population Growth • The Demographic Transition – 1. Low growth – 2. High growth
– 3. Moderate growth – 4. Low growth
• Population pyramids – Age distribution – Sex ratio
• Countries in different stages of demographic transition • Demographic transition and world population growth
What is the Demographic Transition? • The shift from high to low mortality and fertility through four distinct stages. • Based on the experience of Western Europe’s Industrial Age. • Began by Warren Thompson in 1929. • Further developed in 1945 by Frank Notestein • A sign of socio-economic progress?
The Demographic Transition • Stage 1: Low Growth – Very high CBR – Very high CDR – Very low NIR • Stage 2: High Growth – High CBR – Rapidly declining CDR – Very high NIR • Stage 3: Moderate Growth – Rapidly declining CBR – Moderately declining CDR – Moderate NIR
• Stage 4: Low Growth or Stationary – Very low CBR – Low, slightly increasing CDR – Zero or negative NIR
• Stage 5?: Stationary population level (SPL)?
In Depth New Model
Stage 1 - High Fluctuating Birth Rate and Death rate are both high. Population growth is slow and fluctuating. Reasons Birth Rate is high as a result of:
Lack of family planning High Infant Mortality Rate: putting babies in the 'bank' Need for workers in agriculture Religious beliefs Children as economic assets
High levels of disease Famine Lack of clean water and sanitation Lack of health care War Competition for food from predators such as rats Lack of education
Death Rate is high because of:
Typical of Britain in the 18th century and the Least Economically Developed Countries (LEDC's) today.
In Depth New Model
Stage 2 - Early Expanding Birth Rate remains high. Death Rate is falling. Population begins to rise steadily. Reasons
Death Rate is falling as a result of: Improved health care (e.g. Smallpox Vaccine) Improved Hygiene (Water for drinking boiled) Improved sanitation Improved food production and storage Improved transport for food Decreased Infant Mortality Rates
Typical of Britain in 19th century; Bangladesh; Nigeria
In Depth New Model
Stage 3 - Late Expanding Birth Rate starts to fall. Death Rate continues to fall. Population rising. Reasons:
Family planning available Lower Infant Mortality Rate Increased mechanization reduces need for workers Increased standard of living Changing status of women Typical of Britain in late 19th and early 20th century; China; Brazil.
In Depth New Model
Stage 4 - Low Fluctuating • Birth Rate and Death Rate both low. Population steady. – Economy is settled – Fully developed Middle Class – Political stability
• Typical of USA; Sweden; Japan; Britain
In Depth New Model
Stage 5? – Declining Population • • • •
Theoretical Death Rate exceeds Birth Rate. Negative NIR Mostly Eastern European Countries
– Russia – Belarus – Germany – Italy – Japan • Many developed countries are predicted to experience population decline. – Factor of more elderly than young population in these countries – Fewer young women who will be entering their childbearing years – Elderly Support Ratio - The number of working-age people (ages 15–64) divided by the number of persons 65 or older
ELDERLY SUPPORT RATIO
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Is the Demographic Transition Model Still Useful? • How well does the classic model work? • Is it a useful framework for developing countries? • Do developing countries need to share the experiences of Europe and the United States? • Is the socioeconomic change experienced by industrialized countries a prerequisite or a consequence of demographic transition?
Is the model universally applicable? • Like all models, the demographic transition model has its limitations. It failed to consider, or to predict, several factors and events: – 1 Birth rates in several MDCs have fallen below death rates (Germany, Sweden). This has caused, for the first time, a population decline which suggests that perhaps the model should have a fifth stage added to it. – 2 The model assumes that in time all countries pass through the same four stages. It now seems unlikely, however, that many LDCs, especially in Africa, will ever become industrialized.
– 3 The model assumes that the fall in the death rate in
Stage 2 was the consequence of industrialization. In many countries, the fall in the birth rate in Stage 3 has been less rapid than the model suggests due to religious and/or political opposition to birth control (Brazil), whereas the fall was much more rapid, and came earlier, in China following the government-introduced ‘one child’ policy. The timescale of the model, especially in several South-east Asian countries such as Hong Kong and Malaysia, is being squashed as they develop at a much faster rate than did the early industrialized countries. – 4 Countries that grew as a consequence of emigration from Europe (USA, Canada, Australia) did not pass through the early stages of the model.
Population Pyramid
Population Pyramids = graphic device that represents a population’s age and sex composition. Pyramid describes diagram’s shape for many countries in 1800’s when was created.
Population Pyramid Overview • The most important demographic characteristic of a population is its age-sex structure. Age-sex pyramids (also known as population pyramids) graphically display this information to improve understanding and ease comparison. • Age-sex pyramids display the percentage or actual amount of a population broken down by gender and age. The five-year age increments on the y-axis allow the pyramid to vividly reflect long term trends in the birth and death rates but also reflect shorter term baby-booms, wars, and epidemics.
Population Pyramids • The shape of a pyramid is primarily determined by the crude death rate in the community. • Dependency ratio-the number of people who are too young or too old to work, compared to the number of people in their productive years. • People who are 0-14 and 65-plus normally are classified as dependents. • The “graying” of a population refers to the aging of a community. • Population pyramids also foretell future problems from present population policies or practices. Ex. China’s population policies skewed in favor of males.
Dependency ratio • Number of people who are too young or too old to work, compared to the number of people in their productive years • Indicates financial burden on a society’s productive population • Dependency Ratio = measure of # of dependents – old and young that each 100 people in productive years (15 – 64)
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Sex Ratio • The number of males per hundred females in the population is the sex ratio. In Europe and North America the ratio of men to women is about 95:100 • In poorer countries the high mortality rate during childbirth partly explains the lower percentage of women.
There are three key types of population pyramids:
Rapid Growth: This pyramid of the Philippines shows a triangleshaped pyramid and reflects a high growth rate of about 2.1 percent annually.
There are three key types of population pyramids:
Slow Growth: In the United States, the population is growing at a rate of about 1.7 percent annually. This growth rate is reflected in the more square-like structure of the pyramid. Note the lump in the pyramid between the ages of about 35 to 50.
In wealthy countries with very slow rate of population growth – population is nearly equally divided - so pyramids have • Almost vertical sides. • War can be reflected by showing depleted age cohorts and male – female disparities. • The % of a country’s population in each age group strongly influences demand for goods and services within that national economy. • Country with high % of young has high demand for educational facilities and health delivery services.
There are three key types of population pyramids: Negative Growth: Germany is experiencing a period of negative growth (0.1%). As negative growth in a country continues, the population is reduced. A population can shrink due to a low birth rate and a stable death rate. Increased emigration may also be a contributor to a declining population.
Population Pyramids in U.S. cities
Countries In Different Stages of Demographic Transition
Rapid Growth in Cape Verde
Fig. 2-17: Cape Verde, which entered stage 2 of the demographic transition in about 1950, is experiencing rapid population growth. Its population history reflects the impacts of famines and out-migration.
Moderate Growth in Chile
Fig. 2-18: Chile entered stage 2 of the demographic transition in the 1930s, and it entered stage 3 in the 1960s.
Low Growth in Denmark
Fig. 2-19: Denmark has been in stage 4 of the demographic transition since the 1970s, with little population growth since then. Its population pyramid shows increasing numbers of elderly and few children.
2.5 The Demographic Transition
POPULATION PYRAMID AND DEMOGRAPHIC TRANSITION FOR CAPE VERDE (LEFT), CHILE (CENTER), DENMARK (RIGHT) © 2013 Pearson Education, Inc.
Census taking in China
Demographic Transition and World Population Growth • How many countries are in each of the following stages of the demographic transition? – Stage 1- None – Stage 2 and 3- majority of countries (i.e. Egypt, Kenya, India) – Stage 4- USA, Japan, France, UK – Stage 5 – Germany?
Two “big breaks” & their causes • The first break-the sudden drop in the death rate that comes from technological innovation • The second break-sudden drop in the birth rate that comes from changing social customs
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